FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: My427stang on August 18, 2018, 04:55:26 PM
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I have never been happy with the power brakes on my truck, vacuum is around 12 in/Hg and I decided I may try one, but it feels like a band-aid at best to me, waste of money at worst. Anyone use one? Were they magical? Useless? a decent cover-up?
Thinking the tank style, just a reservoir, not something that makes vacuum
I have never had to do it, but about ready to go manual brakes on the F100 so though it may be worth giving it a shot first
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I Have 11in/Hg on the galaxie, And i use a dual diaphragm booster from
a Volvo 740. Since i live in Sweden it was free with a car attached to it,
that i sold for 150$ after i nicked the booster and overdrive ;D
(https://s19.postimg.cc/f634zljur/IMG_3902.jpg) (https://postimages.org/)
Master cyl was a bolt on. I made new brackets between firewall and booster
i used the bellcrank from the original rat trap
(https://s19.postimg.cc/7w7hh61oj/thumbnail_IMG_0205.jpg) (https://postimg.cc/image/88yvncjy7/)
(https://s19.postimg.cc/knlnnnob7/thumbnail_IMG_0207.jpg) (https://postimg.cc/image/8yhnzoxcf/)
It works fine, really light brake pedal quite big booster "canister" so mayby it works like a vaccum canister
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I am already running a dual booster. I don't know why this truck is so fussy with relatively mild cam, but even changing from the stock 8.75 that was 30+ years old to this one made nearly no difference. In the 80s the pedal was at the top and hard, now it's good until you get to a light.
Brakes are new, went from drum to disk out front, bled, adjusted, nothing magically different and not really looking to reinvent anything. in the end, the low vacuum seems to be the culprit. The cans are cheap, my question is whether they make a difference, because I hate to mount something and have it be useless.
(https://s20.postimg.cc/pqrshm8st/Booster._zpshoqdkey6.jpg)
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Never tried one but...I know the Rally guys around here use them
or used them in the past i shall say, dont know nowadays
I have the same problem now with Stepsons Fairlane
Drums front and rear i have to stand on pedal to hold it at idle
Swaped booster to a one that is said to work. No change,
removed the drums and, aha primary and secondary shoes in the
wrong place, at rear two primary on one wheel two secondary on one wheel
bought new shoes turned front drums rear drums was new. Asembled, no change
??? checked the cylinders, rear was wrong and different size ::) front was fine
no change. Dissasembled the master it was full of,,,,,,,,Fudge. bench bled it was
working fine still no better brakes vaccum is 17???
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I’m mulling this over in my head and wondering why since the power assist is in essence a vacuum canister would adding more vacuum volume (for lack of a better description) help. Seems to me if the booster is in good shape all should be well.
Having said that I totally understand about not being happy with the brake performance. As you may remember I went through the same thought process for my ‘61. It stops fine but every now and then it doesn’t give you confidence and you just push harder. It then stops perfectly. It’s fine but not perfect.
Could it be that this is a symptom of the smaller than 9 inch boosters?
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Could it be that this is a symptom of the smaller than 9 inch boosters?
Thus more volume?
But would it make a difference if not contained in the booster?
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No help on vac but I run manual brakes on both of my vehicles with no issues. I can lock them up and with even a mild converter it’s no effort to hold at idle.
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Do you have a one way valve on the hoose to the booster?
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Question, what is the size of the mastercylinder? Is it for a disc/drum or disc/disc system? That would be a contributor to the problem. Go to MP brakes, they have a problem page that may shed some light on your problem. On my 56 F100 they were real helpful on why my brakes felt like it didn`t have any pressure to them. By the way I have disc/disc non power and it stops on a dime.
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For front disk brakes you need to run at least a 9 inch booster. As GJCAT427 said ring MP Brakes and ask them about your setup.
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https://www.summitracing.com/parts/crn-99590-1/overview/
Same problem on my 393C in my 73 mustang, this made a huge difference.
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I have used one for the last 20 years although hoping an impending cam change will render it obsolete.
My 390 only makes (made) 6.5" at idle which is obviously useless for PB. However it does generate more (not sure what) on closed throttle over run situations & this is usable. So all the tank does is give you another couple of reasonable pushes before sphincter clenching sets in. The tank coupled with the braking technique where by you don't release the pedal all the way if you know another push is coming, thus keeping that charge, makes the car easily drivable with PB.
I made my tank from truck exhaust (about 6" OD) welding plates on each end and some brackets to mount up behind the headlight. Hose goes from the manifold into the tank with a booster check valve mounted on it. Next to this is a hose tail which then goes to the booster which retains its valve also.
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i use a canister, if you only have 12 in of vacuum, a can won't help, you'll need more than 12 to run a booster, the can will only maintain the 12 in,
not increase it.
i have 6 inches of vacuum, i run a vacuum pump and plumb it into the can to run my power brakes.
get a good one they aren't cheap, the inexpensive ones aren't worth doo-doo
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I have the same Crane canister on my '70 351W Mach 1 and it does work great.
https://www.summitracing.com/parts/crn-99590-1/overview/
Same problem on my 393C in my 73 mustang, this made a huge difference.
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Ross,
Like an earlier poster said, make sure the MC is for disk/drum not drum/drum etc...likely it’s correct.
Also, since it was originally a drum/drum truck the brake valve down the line would have to be changed. For drum/drum trucks ford called it a different name but most refer to it as a proportioning valve. I doubt you missed that but you never know. When going to discs you have to change this out or the pressure to each end will not be correct and the system will function poorly. Best to put an adjustable one in place.
Otherwise I would say there is another issue. One way valve comment being bad/missing is an easy check.
Good luck
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I appreciate all the responses, I didn't put the whole chain of events that got me here
- Truck had incredible stock drum/drum power brakes. Pedal right at the top little effort, this was with stock 302, stock 351, and later stock 360, and a mild (270H) 390 ..... going back 30 years here, brakes were incredible, even for drums
- Sat for 14 years, 2007 rebuilt stock brakes, all new name brand stock stuff, brakes were OK, but never like they were
- Built the stroker, had lower vacuum, (same 12 in or so) pulled vacuum on the stock booster, it was leaking, 46 years old, no surprises, replaced it with a dual 7.5 inch designed for lower vacuum. Master sized accordingly during purchase and bought for discs
- Had issues with the stroker, built a "bench motor" mild cam, 390 cid, bench motor only has 12 in of vac at 600 rpm idle. Also I always wanted discs, built a complete front end with all new brake parts, factory 1979 F150/Bronco parts.
- Off idle brakes are great, idle, brakes have some travel then hard pedal. Checked booster 1 way valve, wasn't a perfect seal, so replaced it. No difference in behavior.
- So, the bench motor is a temp and runs like a sweetheart, nothing significant to gain through timing and carb adjustment and it isn't coming apart until the 462 is ready. Not because I don't care, but because it's just a temp and runs like a swiss watch. Since brakes are all new, and constant was the low vacuum, figured maybe a band aid with a tank
However, since then, Brent and I were BSing in our normal knitting circle conversations and deduced that maybe I can get a little vacuum by raising the idle. I'll see today. The thing sounds so mild that I dropped idle to the dirt to try to get it to sound like something through the 3 inch pipes LOL but there is no reason it needs to idle so low. I can try raising it a few hundred RPM and see if vacuum comes up
If it is what it is, the discs suck a little compared to the drums because they used to self-energize a bit, but it will be OK until the 462 is done, because I don't really want to mount a tank under there, but if the tank was very effective, it'd be a cheap short term solution
Thanks everyone!
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I don’t know, but if you tell anyone else about our knitting circle, I’ll never talk to you again.
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I don’t know, but if you tell anyone else about our knitting circle, I’ll never talk to you again.
Fo real....
Anyway, bridge on Wednesday and don’t forget to bring your potato salad for the book club tomorrow.
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I don’t know, but if you tell anyone else about our knitting circle, I’ll never talk to you again.
Fo real....
Anyway, bridge on Wednesday and don’t forget to bring your potato salad for the book club tomorrow.
Brent - First rule of fight club....
Drew - My wife is a librarian, you don't know how true your statement is around my house. I come in from the garage and wash my hands, jaws drop, and not for my dashing good looks
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I don't knit, but I'm a fair baker, need an XL apron.
About drum to disc - don't disc brakes need more pressure? I've been toying with going to discs up front (on a '69 F100 4WD there are limited options for bolt on but SSBC has a kit I'm eyeing). One of my reservations is that I don't have huge vacuum now, and the drums are just ok (engage well but require a fair bit of leg).
I also would like to go to a smaller diameter booster for valve cover clearance, but I'm afraid that a smaller diameter will be less responsive (smaller surface area for the vacuum to act on).
Been idly wondering about going to a vacuum pump, but haven't really dug in on the subject.
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A few more RPM wont hurt - but a closed throttle will generally add vacuum. You could raise idle with a bit more base timing??? Also check to see if all the blades in the barrels are centered and closed up evenly - one that is open more might make closed throttle a bit tougher to nail down. My '46 has the problem with a really hard pedal and a small diameter booster. Guys that sold me that kit a decade or two ago say they have gone to a 1/8 smaller diameter master cylinder bore to help the problem, which they were aware of. Have not tried that yet but I will...
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Here's another setup for fyi.
My 65 Thunderbird has lots of vacuum accessories, large discs up front and drums rear. I put an 8" dual diaphragm booster on for tall valve cover clearance and added a 1" dual master cylinder.
Expecting the stroker to be light on vacuum I installed a vacuum pump to supplement things.
The Tbird has several canisters which do add a little capacity for pumping breaks and the nice part is they retain the higher vacuum from the vacuum pump assist. The engine is isolated with 1 way valve from the rest of the system and the booster is directly off of 1 canister which is also isolated from the rest.
Breaking with this system is excellent, yes there is a pump but it does not run much at all since the engine is getting me to around 12 (likely higher when I let off the gas) and the pump just needs to take it to 17 or so.
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Here's another setup for fyi.
My 65 Thunderbird has lots of vacuum accessories, large discs up front and drums rear. I put an 8" dual diaphragm booster on for tall valve cover clearance and added a 1" dual master cylinder.
Expecting the stroker to be light on vacuum I installed a vacuum pump to supplement things.
The Tbird has several canisters which do add a little capacity for pumping breaks and the nice part is they retain the higher vacuum from the vacuum pump assist. The engine is isolated with 1 way valve from the rest of the system and the booster is directly off of 1 canister which is also isolated from the rest.
Breaking with this system is excellent, yes there is a pump but it does not run much at all since the engine is getting me to around 12 (likely higher when I let off the gas) and the pump just needs to take it to 17 or so.
So educate me a little about pumps. How is it piped, and what are you running?
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Yellow Truck if you run Power stearing you can run
a hydroboost for the brakes and use the P.S pump
for that
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Hydroboost is a good way to go as well, I just wanted to make sure I had good vacuum for everything in the car so I went the pump route.
Many pumps out there, bought a CVR for about $300, seems to be working fine although the vacuum sensor was bad on the first unit but got a replacement for free, so far the pump is fine but not that many hours on it yet. Wired to turn on with ignition. Kind of a nice safety back up, if engine dies I still have vacuum.
Many ways to skin the cat plumbing wise, I chose run an isolated leg for the brakes with it's own canister and another isolated leg for accessories. Both legs are fed by engine vacuum but as i stated there is an in-line one way valve right at the manifold to make sure the engine is not depleting system vacuum when it is not making making much. With no isolation of course the engine wins by volume and the pump would run constantly.
I suspect with a couple canisters, tbirds happen to have 2, you could run with just the pump if your system is tight, would not cycle often at all except maybe when braking a lot in heavy traffic, no real need for any engine vacuum. Boosters eat a lot of volume though so a good size reservoir is a must.
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I have run one since I got my drivers license. I learned how to use it to my advantage over time. The one I have is the aluminum body canister style from summit. Some notes:
-the comment about it only pulling 12" is inaccurate. Downshift before applying the brakes or coast some beforehand will generate a spike in vacuum that the check valve should maintain. That's part of what I adapted into my driving style to help
-it works fine if you pay attention and plan your slower/casual stops accordingly. You really only get one good stab of the pedal before you're back to leg-press mode. So, if you're coasting up to a red light and have a habit of kind of bumping the brakes multiple times rather than judging the distance/braking needs more carefully, you're going to want to change that. This is especially important for situations where you might be trying to get across oncoming traffic and have a small window to do so. You only get one good vacuum assisted stab of the pedal. This will put you up on a curb in short order.
-you will learn how to manipulate and best use it in time if you just pay attention to the limitations of it, after the install. After that, it works just fine in my opinion.
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I have run one since I got my drivers license.
Have you actually had enough time since then to buy a second?
Sorry, I can't help it.
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Yes i run one it works good i had a ele pump but it was to noisy.
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My opinion isn't worth much, but I don't think it's vacuum. I think it's the junk Chinese GM dual booster you bought from Pirate Jack.
I saw your post on Fordification and bought the same setup. Aside from the extremely poor quality of the kit, I'm not all that impressed with the function. New hard lines front to back, new cylinders in the rear, new calipers up front, new soft lines.....bled all 4 corners 3 times. I can't lock up my brakes if I wanted to. And the fronts are 12" disks!
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Jim, certainly not saying you are wrong, because I expected the booster and master cyl swap to make a heck of a difference, but I have very good brakes when vacuum is up.
I don't think the vacuum can will be right for me, but not sure I am ready to give up on the setup yet. I'll take it out this weekend and diagnose a bit more.
What was poor quality in your kit? It used some cheap looking brackets and bell crank, but I didn't even use those, I just bolted the booster in place and swapped to the correct line ends, it was pretty much a bolt on for my 71 4x4
I appreciate the input though, hate to hear you bought something based on my purchase and it didn't work out
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No worries Ross. It's not like I didn't know what to expect from an eBay sale.
http://www.fordification.com/forum/viewtopic.php?f=22&t=83642&start=90#p742625
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Still think the easiest, cheapest, fastest fix is a canister. JMO!
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Still think the easiest, cheapest, fastest fix is a canister. JMO!
I am being cheap and stubborn about mounting one under the hood, but maybe I'll hang one temporarily and see what it does. Certainly the easiest and if it did what I needed, it's the easiest answer. Thanks!
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A similar discussion is being had on the Boss 302 forum. In that discussion the Hella up28/30 pumps were brought up as a viable quiet option. Apparently the up28 for assit and up30 as an alternative engine vacuum. I have no experience with either but these are apparently used on Volvo production vehicles.
Random howto article: http://www.electricsubaru.com/vacuum.html
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Thanks Jmlay, My son is scraping a Volvo V70
then i shall rescue the vaccum pump from that
for future needs
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Jim, certainly not saying you are wrong, because I expected the booster and master cyl swap to make a heck of a difference, but I have very good brakes when vacuum is up.
I don't think the vacuum can will be right for me, but not sure I am ready to give up on the setup yet. I'll take it out this weekend and diagnose a bit more.
What was poor quality in your kit? It used some cheap looking brackets and bell crank, but I didn't even use those, I just bolted the booster in place and swapped to the correct line ends, it was pretty much a bolt on for my 71 4x4
I appreciate the input though, hate to hear you bought something based on my purchase and it didn't work out
My truck with the 482 only has 8" vacuum. Pedal pretty much solid. If engine vacuum is way low not so sure a canister will work. Most boosters need 15" to work properly. I have been looking at vacuum pumps. Pricey but think that is route to go.
https://www.summitracing.com/search/part-type/vacuum-pumps-street?SortBy=DisplayPrice&SortOrder=Desc&tw=vacuum%20pu&sw=Vacuum%20Pumps%2C%20Street&N=4294871448
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Thanks, I have used a pump/canister combo on a pretty rowdy Rat in a 55 Chevy that couldn't decide if it was a street rod or drag car, and yes it worked great. (I just hate to spend the dough :)
Isn't it funny, as a young man paycheck to paycheck, I loved to spend, now when I have it, I am a cheapskate LOL
I have some things I need to do with the proportioning valve, I don't like the bias and the one I have isn't adjustable, so I need to do that first and see what I think about the brakes, then make a call.
Believe it or not, as you know, the F100 is so light in the rear, I likely would be more happy in the long run with a little more cam in the stroker and a nice pump/canister to make up for the brakes, but I tend to decide pretty slowly
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I had thought that too (low engine vac) but after reading how a canister works, I got one. See, on deceleration, even the hottest engines produce 15-20 inches of vac that 'fills' the canister. Before engine vac. drops back to low levels, the one-way valve captures that high vacuum for use later while braking. If one does heavy road-racing with constant turns (braking) one would deplete the canister pretty quickly. For almost all street and highway use where constant and heavy braking is not employed, it's fine.
Jim, certainly not saying you are wrong, because I expected the booster and master cyl swap to make a heck of a difference, but I have very good brakes when vacuum is up.
I don't think the vacuum can will be right for me, but not sure I am ready to give up on the setup yet. I'll take it out this weekend and diagnose a bit more.
What was poor quality in your kit? It used some cheap looking brackets and bell crank, but I didn't even use those, I just bolted the booster in place and swapped to the correct line ends, it was pretty much a bolt on for my 71 4x4
I appreciate the input though, hate to hear you bought something based on my purchase and it didn't work out
My truck with the 482 only has 8" vacuum. Pedal pretty much solid. If engine vacuum is way low not so sure a canister will work. Most boosters need 15" to work properly. I have been looking at vacuum pumps. Pricey but think that is route to go.
https://www.summitracing.com/search/part-type/vacuum-pumps-street?SortBy=DisplayPrice&SortOrder=Desc&tw=vacuum%20pu&sw=Vacuum%20Pumps%2C%20Street&N=4294871448
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Thanks, I have used a pump/canister combo on a pretty rowdy Rat in a 55 Chevy that couldn't decide if it was a street rod or drag car, and yes it worked great. (I just hate to spend the dough :)
Isn't it funny, as a young man paycheck to paycheck, I loved to spend, now when I have it, I am a cheapskate LOL
I have some things I need to do with the proportioning valve, I don't like the bias and the one I have isn't adjustable, so I need to do that first and see what I think about the brakes, then make a call.
Believe it or not, as you know, the F100 is so light in the rear, I likely would be more happy in the long run with a little more cam in the stroker and a nice pump/canister to make up for the brakes, but I tend to decide pretty slowly
Ross,
Did you remove the factory distribution block when you did the swap? I mentioned this when the issue first hit the forum. A disc/drum disc/disc system will not work correctly with it in the system. I am betting you swapped it but just curious. I think an adjustable proportioning valve will work better..if not, a can is a cheap last try.
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What exactly is wrong with manual brakes?
Not getting it, sorry
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What exactly is wrong with manual brakes?
Not getting it, sorry
Nothing, but the truck bought by my grandfather new and I have driven since 1984 has power brakes....my Mustang is manual brakes and disk/drum, but the 4500 lb 4 inch lift truck, I'd like to work the way I want.
Thanks, I have used a pump/canister combo on a pretty rowdy Rat in a 55 Chevy that couldn't decide if it was a street rod or drag car, and yes it worked great. (I just hate to spend the dough :)
Isn't it funny, as a young man paycheck to paycheck, I loved to spend, now when I have it, I am a cheapskate LOL
I have some things I need to do with the proportioning valve, I don't like the bias and the one I have isn't adjustable, so I need to do that first and see what I think about the brakes, then make a call.
Believe it or not, as you know, the F100 is so light in the rear, I likely would be more happy in the long run with a little more cam in the stroker and a nice pump/canister to make up for the brakes, but I tend to decide pretty slowly
Ross,
Did you remove the factory distribution block when you did the swap? I mentioned this when the issue first hit the forum. A disc/drum disc/disc system will not work correctly with it in the system. I am betting you swapped it but just curious. I think an adjustable proportioning valve will work better..if not, a can is a cheap last try.
Yes, and initially used a 79 Bronco valve, but the truck is lighter and more nose heavy, I am not happy with it. FYI, the can is solving a different issue than the proportioning valve, one keeps the rears from locking up, the other gives me a solid pedal. Although you are correct, if some reason I am happy with it after I get the bias where I want it, I'll be good
I had thought that too (low engine vac) but after reading how a canister works, I got one. See, on deceleration, even the hottest engines produce 15-20 inches of vac that 'fills' the canister. Before engine vac. drops back to low levels, the one-way valve captures that high vacuum for use later while braking. If one does heavy road-racing with constant turns (braking) one would deplete the canister pretty quickly. For almost all street and highway use where constant and heavy braking is not employed, it's fine. , the rears lock first.
Bob, can't hurt to try. I follow you 100%, maybe I will buy one and strap it somewhere under the hood for now. Hate to drill my fancy NOS inner fenders unless I have to. It's no show truck but those were NOS in 1995 and sat in a box and I hate to drill holes in them unless I am sure :)
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Ross I don't know how much room you have behind the grill but here is were I put mine on my 73 mustang. Your a smart cookie you will get it figured out, good luck. Dan
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Thanks, I have used a pump/canister combo on a pretty rowdy Rat in a 55 Chevy that couldn't decide if it was a street rod or drag car, and yes it worked great. (I just hate to spend the dough :)
Isn't it funny, as a young man paycheck to paycheck, I loved to spend, now when I have it, I am a cheapskate LOL
I have some things I need to do with the proportioning valve, I don't like the bias and the one I have isn't adjustable, so I need to do that first and see what I think about the brakes, then make a call.
Believe it or not, as you know, the F100 is so light in the rear, I likely would be more happy in the long run with a little more cam in the stroker and a nice pump/canister to make up for the brakes, but I tend to decide pretty slowly
Since I have large 14" 6p brakes I went with the matching 1" Master Cylinder and has a built in proportioning valve that's a option. Only drove once around the block so far but once I get some proper vacuum to see how it all works out.
(http://img.photobucket.com/albums/v513/CalypsoCoralBoss302/1966%20F100%20482/17518F24-4976-4801-B6AA-43E548F48ACB.jpg)
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I had thought that too (low engine vac) but after reading how a canister works, I got one. See, on deceleration, even the hottest engines produce 15-20 inches of vac that 'fills' the canister. Before engine vac. drops back to low levels, the one-way valve captures that high vacuum for use later while braking. If one does heavy road-racing with constant turns (braking) one would deplete the canister pretty quickly. For almost all street and highway use where constant and heavy braking is not employed, it's fine.
Jim, certainly not saying you are wrong, because I expected the booster and master cyl swap to make a heck of a difference, but I have very good brakes when vacuum is up.
I don't think the vacuum can will be right for me, but not sure I am ready to give up on the setup yet. I'll take it out this weekend and diagnose a bit more.
What was poor quality in your kit? It used some cheap looking brackets and bell crank, but I didn't even use those, I just bolted the booster in place and swapped to the correct line ends, it was pretty much a bolt on for my 71 4x4
I appreciate the input though, hate to hear you bought something based on my purchase and it didn't work out
My truck with the 482 only has 8" vacuum. Pedal pretty much solid. If engine vacuum is way low not so sure a canister will work. Most boosters need 15" to work properly. I have been looking at vacuum pumps. Pricey but think that is route to go.
https://www.summitracing.com/search/part-type/vacuum-pumps-street?SortBy=DisplayPrice&SortOrder=Desc&tw=vacuum%20pu&sw=Vacuum%20Pumps%2C%20Street&N=4294871448
I should have noted I plan on doing some AutoCross and hoping for some longer road course events. Reason for the road race oil pan etc.
Even for stop n go traffic do not think the canister alone will cut it. Did that on a '56 Chev but did not work so well.