Weak Brakes

[lars]

I nearly went this rute during inital purchase and was hesitant for double the price. I should have gone this rote to begin with I bet. What is the best path to follow for this upgrade? Parts house, salvage? Should I ditch the proportoning valve and just go with an adjustable?

Anyone what to purchase a nearly new vac booster and MC. Less than 1k miles.

Dave

Do a hydroboost search on this site before making any decisions. There are zillions of threads and lots of good information. Junkyard swaps are perfectly viable and cheap, as long as you don't mind a little fab work. I sold my vacuum setup on Ebay for enough to cover most of the hydroboost cost. It would have covered all of it if I hadn't gone with a brand new master cylinder, but I don't like used ones so it was worth it to me. You could re-use the one on your vacuum booster but the brake lines hook up on the wrong side when attached to the h-boost unit, making the connections awkward.

However you go about it I can guarantee you'll be happy with the results.

 

[lars]

p-valve

Oh yeah: proportioning valve. Again just my opinion, but I say ditch it and use an adjustable one. New Wilwood valves are only something like $50 at Summit. Then you can easily get the brake balance correct. If you have a Ford p-valve you can probably sell it for more than the cost of the adjustable one. I did, though maybe I just go lucky.

 

[DanWheeler]

Hydroboost is probably great - thats the way I'm going eventually but you should try to fix what you have. If you get it working right it SHOULD work very well. At least give it a try.

 

[Apogee]

Oh yeah: proportioning valve. Again just my opinion, but I say ditch it and use an adjustable one. New Wilwood valves are only something like $50 at Summit. Then you can easily get the brake balance correct. If you have a Ford p-valve you can probably sell it for more than the cost of the adjustable one. I did, though maybe I just go lucky.

FYI...the Summit brand labeled proportioning valve (SUM-G3905) is identical to the Wilwood unit (WIL-260-8419) except it costs about $6 less, which almost covers their handling fee

My vac assist brakes work fine and I'm not even sure the rears are doing anything after my last wheel bearing incident. I'm only running 33's at this point, but will consider a different braking solution when I step up to 37's.

 

[TOFIC]

Crappy brakes!!

WELL here is the old guys kick at this one.

There things leap out on me. actually four
1. master cylinder
2. actuating rod under dash
3. Pinched line on the rear brakes.
4. you should see this one coming HYDROBOOST.

Master Cylinder, with the statement that you get some braking power and you get to one point and it stops kinda kicks me in this direction. Four wheel disks make sure you are running a 4 wheel disc master. I like the Lincoln one but there are others. Dont assume a new one is good, make sure you bench bleed the master before you install it. Also ensure that the valve in the master moves correctly when you are bleeding it.
Actuating rod, check this thoroughly!! Make sure it moves smoothly and effortlessly when you install it on the pedal. Check this by taking the Master off and trying the pedal actuation. This must move smoothly and without hestitation in the direction you want.
Pinched line, not pinched closed, just pinched Go over the whole system very carefully and look for this. This one is not easy to find but it is real obvious when you find it.
HYDROBOOST!!! cheaper than vacuum, easier to install, smaller physically in size than vacuum and 10 times more powerful!! (guess who wrote the hydroboost article?)
TOFIC

 

[lars]

guess who wrote the hydroboost article?

Maybe so, but I'm disappointed that it took until the second page of posts before you managed a response to this one

 

[Pa PITT]

T O F I C

yes that's what i was thinking ..where is he with his 2 bits worth...
to me his advice is the best on this brake issue....
seems to have grown up on these...
PA PITT...

 

[Cactus killer]

A proportioning valve is Bandade, covering up the problem of an unballanced brake system. I have 37" tires and PB with 4 wheel disc and the stock H block and it stops just fine. Brfore you waste your money on new parts look at the small details like. Are the calipers on the correct sides with the bleeders at the highest point(with the Chevy set up are the calipers hitting the Knuckles, as the pad wears out it will move over). Does the brake peddle have 7" of travel. Do you have old rubber lines if they are old sometimes you can see them swell up when you hit the brakes, causing spongy brakes. Are the brake lines to the master going to the correct brakes, The line near the bracket goes to the front, the one near the front of the Bronco goes to the rear brakes. Inspect all of your lines for kinks. The H valve is just a place to bolt the lines to the frame, it does not effect the brakes at all. It also has a little switch that tells you if the front or rear brakes lost pressure like you couldn't tell on your own. The fluid from F to R do not mix at all so the only way for it not to work is if it got pluged up. Check these things first get it fixed then if you want upgrade. At 20mph you should be able to stop 40"S just fine.

 

[Dsquared]

Sounds like you've gotten a lot of good responses/ideas. Sorry it took awhile to get back, I've been out of town. I mentioned I was having similar problems with similar set up. I have 33's and vacuum boost with propotion valve and chevy disc set up. All new parts. Double check all the basics. I had one line crossed up on PV and it screwed everything up. I got that corrected and the booster adjusted properly and mine are working great now. Will lock up on 33's. I would try and fix what you have before spending money on different set up.