Ok, been driving my old truck around. A few weeks ago my drivers caliper was sticking. I changed it out. Now, both are sticking. The pedal gets firmer as l drive it. I have adjusted the rod until l have almost worn out the threads. The only thing that l did not do was put a residual thing for the drum breaks in the rear. I thought that there was a residual thing in the porportioning valve. Thanks
Yes forgot to say it is all 100% new. I got a kit from pirate Jack. It is a Fatman Fab mustang 2 front end.
Sounds like a problem I had and just learned from. Make sure you have a little "slack" in the plunger rod. If the plunger cannot completely extend back out, pressure builds slowly until they lock up. I'll bet that's your problem. It took me 3 MCs before I asked the question here and got it figured out. Sent from my iPhone using The H.A.M.B. mobile app
I was just messing wirh it. It seems like the booster boosts a little when it gets vacuum. I took it apart but it doesnt look like there is an adjustment on the rod between the mastercylinder and the booster
Each MC I had had a slightly different length rod. Yours could be a problem with the booster. I can only speak from my experience. Just make sure you are getting complete return or pressure will build over time. Sent from my iPhone using The H.A.M.B. mobile app
I have adjusted the rod going to the booster a dozen or so times. I split the booster and master cylinder and the rod between the two doesnt seem to be adjustable.
On mine I actually had to cut it to the correct size and tig weld it back together. Definitely NOT saying you are in the same boat as I was but it does sound like somewhere in the linkage there is something not allowing the MC to return all fluid to the reservoir and thus gradually increasing the pressure. Best of luck as I know firsthand how frustrating that shit can be. Sent from my iPhone using The H.A.M.B. mobile app
Try shimming the master cylinder out with washers to see if it solves the problem. It could also be a bad booster.
plug the line going to the booster and drive it . if the brakes do not start draging then it is the booster. [ i got 2 bad boosters from summit .]
Buddy of mine had same problem going to NRSA York. He took it to the repair shop and they installed washers between the booster and M/C. problem solved.
So l finally got to mess with it. I disconnected the vac line from the engine and capped the vacuum port. I drove car around for a few miles and front brakes still started to drag pretty bad if l take it out of gear it will cone to a complete stop.
I'm tellin ya, pressure is building and it is likely because the internal calving IN the MC is not being allowed to fully open. I had just a hair tension on the plunger and the same thing kept happening. It wasn't until I positioned the plunger to fully extend, WITH PLAY, that the problem went away. I literally fucked with mine for 3wks before the HAMB came to my rescue. Lesson learned....the hard way. Sent from my iPhone using The H.A.M.B. mobile app
Yes l am getting 100% return from my rod on my pedal. I split the unit ans the rod between the booster and MC did not seem to be adjustable. I have been messing with it for a few months but just got it legal to drive a few weeks ago
Man, that sucks! I feel for ya. I was the same way. Got mine legal and then noticed the gradual pressure build with the brakes. Spent three weeks f'n with them. I can't tell you how good I am at bleeding brakes and how damn fast I can do it now. I really hope you figure it out but make sure you post back here on the forum once you figure it out. Maybe someone else will be spared the mess in the future. ;-) Grant
Yea l have one of those hand vacuum pumps and have actually hooked it up to a electric vacuum pump and it is a lot faster!! I let the truck run for a hour without driving it without the booster hooked up to see if heat was affecting it but, the brakes were fine. I have a engine swap planned with my sons car on Saturday but, will try to work on it some tomorrow
call the mfg and see if they have a tech depart I bet when it is sorted out it will be something simple. Tom
I had the same problem.....loosen up the nut on the push rod in the booster...there should be a nut on the push rod no? If so loosen it and turn in the push rod a couple of turns and retighten it. Take it for a cruise...if it still does it do the previous steps again...now I went too far and it stopped dragging but I had a soft pedal...turned it back counter clockwise and now all is good. I had busted a mounting stud on my booster and installed a new one And it wasn't adjusted correctly. Sent from my QMV7A using The H.A.M.B. mobile app
Generally, there should be about .040" to .060" (1 to 1 1/2 mm) clearance between the booster output rod and master cylinder primary piston, and this is checked with full vacuum in the booster, or about 20" Hg. The name "Pirate Jack" for a brake supplier got me to question their products, but some of their incorrect "tech support" was enough to avoid the company. Hopefully, they will work with you on your problem.
Unfortunately I would expect PJ to be a firm that manufactures nothing, no doubt they buy from China and the items they market were reverse engineered from name brands made in the US. For example they sell a brake booster with a master cylinder that looks familiar, in fact they state that it is Wilwood "style". I looked at their website this morning and the FAQ section is blank, probably about like the owner's brain. JMO, but I doubt you will get satisfaction from PJ. Follow the advice and adjust the push rod as others have said. The m/c piston is not retracting enough to uncover the fluid return port in the reservoir.
Most common problem i use to have on my dayly drivers is the calippers that stick. At least one time a year i have to unstick them usally by pump them out and pull them in again. Most becouse we got a lot of rain on summer and salty roads at winters. I have really have come to hate discbrakes over the years. If the calipper dont stick i got rusty discs. Often i have to change them every second year. Drums just need some adjustments from time to time and just work flawlessy.
Since it does it with no vacuum on the booster, it has to be that the master cylinder is not returning fully. If the rod between the booster and the master cylinder is not adjustable, you will need to shim the master cylinder to increase the distance between them.
I didnt have time to mess with it today. I was out chasing crap for a engine swap for one of my kids DD. I kinda ruled out the booster when l unhooked the vacuum and it still did it. I will seperate again and check if there is any adjustment between the booster and master cylinder. I am old and maybe l just didnt look good enough. If l can not get any adjustment shims are my next option!! I was skeptical of PJ but, they sell the same stuff everyone else sells and l have been on a poor mans budget for most of my life. Thanks everyone for the replys!!!!
OK, step by step, a 10 minute test and a drive. 1) Unbolt the master from the brake booster. 2) Add 2 flat washers the correct size as the studs on the booster, to each master cylinder mounting stud. 3) Bolt the master cylinder back on the booster with the flat washers between the booster and the master. 4) Be aware that the brake pedal will now travel farther, and will stop closer to the floor. 5) Carefully drive the car, your testing to see if the brakes are still hanging up. 6) Report back. We will offer a fix after we hear the results of this test. Gene
If shimming the master cylinder cures the problem, the only real fix is returning the booster/master if the booster output push rod is not adjustable. You don't want to use shims permanently as this can cause undue stress on the studs and cylinder housing as well as allow dirt/moisture into the master bore and booster. The booster and master have to be matched pair, or have available adjustment for proper booster to master clearance.
I will bouble check the rod between the two. I put a socket on it and it just spun but, l dont think l had my reading glasses on
Ok l finally made some time to work on it. I added some washers between the booster and the MC. I drove the truck to town and the brakes started dragging just like the always have. I drove it back home and l disconnected the MC and the brakes did not release. It has to be a bad master cylinder. Not sure what else it can be?
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