flathead Posted September 17, 2012 Report Posted September 17, 2012 I've completely replaced every component of my brake system, except for the master cylinder, which I ended up rebuilding. Anyway, bled the brakes and remove all air from the lines, now pumping fluid out, but absolutely no pressure at the pedal. I'm at my wits end on this... Quote
Don Coatney Posted September 17, 2012 Report Posted September 17, 2012 Did you follow the correct procedures to adjust the shoes to the drum? Quote
4msfamly Posted September 17, 2012 Report Posted September 17, 2012 make sure there's a bit of slack where it goes into the master (about 1/4 to 1/2")... you don't want it too tight to the master, otherwise the system can't refill on the upstroke. Good luck! Marc Quote
TheMoose Posted September 17, 2012 Report Posted September 17, 2012 are you seeing any fluid at any wheel cyl? Little things like not starting with the farthest wheel cyl first will give you problems too. I bled my brakes with a vacuum bleeder & it worked 1st time. Quote
pflaming Posted September 17, 2012 Report Posted September 17, 2012 I had the same thing happen to me. So I scrapped the OE MC and put in a 97 Wrangler dual MC. Got GOOD pedal ALL the time now. A bit of work, but for me well worth the effort. Quote
flathead Posted September 17, 2012 Author Report Posted September 17, 2012 are you seeing any fluid at any wheel cyl? Little things like not starting with the farthest wheel cyl first will give you problems too. I bled my brakes with a vacuum bleeder & it worked 1st time. Yes, began at the right rear, lots of air came out, now fluid. Each cylinder has been bled, just no brake pedal pressure... Quote
flathead Posted September 17, 2012 Author Report Posted September 17, 2012 make sure there's a bit of slack where it goes into the master (about 1/4 to 1/2")... you don't want it too tight to the master, otherwise the system can't refill on the upstroke.Good luck! Marc I will verify when I get home, but I think I have about 1/8" of end play at present Quote
Dave72dt Posted September 17, 2012 Report Posted September 17, 2012 I seem to recall a post not too long ago regarding 1/4 inch lines versus 3/16 inch. Pull your lines off at the tee and plug them. If you get pressure, your master is OK. Then replace one line at a time and check for pressure. That should tell which direction to look. Quote
Jeff Balazs Posted September 18, 2012 Report Posted September 18, 2012 If we are talking a stock braking system (and I believe we are based on your earlier posts) then I think either the M/C is bypassing or there is some sort of blockage in the tubing close to the M/C. If you follow Dave's suggestion you should know very quickly. When I started working on my truck after it had sat unused for many years the entire braking system was a write off. As I dug into it I found that All of the hard lines and cylinders were heavily corroded and beyond saving. They did not look bad from the outside.....but they were a mess internally......so just keep this in mind if you are trying to reuse any of the old system. Jeff Quote
JBNeal Posted September 18, 2012 Report Posted September 18, 2012 When I re-worked the brakes on the '48, I ran into the same problem. I found that the bore of the MC had pitted from moisture in the brake fluid. The new rubber in the MC could not seal off the bore enough to build hydraulic pressure, but the MC piston was able to move some fluid through the lines as fluid would also bleed past the MC piston. I ended up getting my MC sleeved for about $150 since I was not able to locate a NORS unit back in '99. I drove the truck the other day, and the brakes still hold pressure Quote
52b3b Joe Posted September 18, 2012 Report Posted September 18, 2012 I had the exact same problem. I struggled for days with it, I put the master cylinder together wrong, I had the order of two things backwards. I would have never guessed it, but my dad knew it as soon as I asked, I guess he speaks from experience. I had the rubber washer in the wrong location. The system would bleed out good, but the pedal would hold ZERO pedal. Its worth looking into if you can't find anything else wrong. Quote
flathead Posted September 18, 2012 Author Report Posted September 18, 2012 I had the exact same problem. I struggled for days with it, I put the master cylinder together wrong, I had the order of two things backwards. I would have never guessed it, but my dad knew it as soon as I asked, I guess he speaks from experience. I had the rubber washer in the wrong location. The system would bleed out good, but the pedal would hold ZERO pedal. Its worth looking into if you can't find anything else wrong. What is the order? My MC kit had no instructions with it Quote
HanksB3B Posted September 18, 2012 Report Posted September 18, 2012 (edited) RockAuto $91 Now why would you rebuild the complete brake system and not install a new Mastercylinder? Maybe someone is trying to save your life by giving you this problem? Hank P.S. Brakes: Not a place to save money. It's your choice: RockAuto $91, VintagePowerWagons $149, Roberts Motor Parts $210. Edited September 18, 2012 by HanksB3B Quote
flathead Posted September 18, 2012 Author Report Posted September 18, 2012 RockAuto $91 Now why would you rebuild the complete brake system and not install a new Mastercylinder? Maybe someone is trying to save your life by giving you this problem? Hank P.S. Brakes: Not a place to save money. It's your choice: RockAuto $91, VintagePowerWagons $149, Roberts Motor Parts $210. Good point. I suppose $100+ vs. $17 for a kit Quote
HanksB3B Posted September 18, 2012 Report Posted September 18, 2012 Oh I understand the $17 vs $100 on anything other than the brake system. Hank Quote
52b3b Joe Posted September 18, 2012 Report Posted September 18, 2012 Look here: http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=13534&highlight=master+cylinder+diagram Quote
flathead Posted September 18, 2012 Author Report Posted September 18, 2012 Look here:http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=13534&highlight=master+cylinder+diagram This may be the answer; my kit did not have that rubber washer they spoke of. Hmmmm.... Quote
flathead Posted April 4, 2013 Author Report Posted April 4, 2013 WOW what a difference a NEW master cylinder makes! LOL I would have had it sooner had I not been so cheap. I bought a new one off of Amazon for $70.27 with FREE shipping! Everything now works (as far as the brakes) Thanks all for the advice you offered, I do appreciate all of it 1 Quote
1952B3b23 Posted April 5, 2013 Report Posted April 5, 2013 Glad to hear your problem is solved. I agree with Hank the brake system is not a good place to try and save some bucks. Quote
HanksB3B Posted April 5, 2013 Report Posted April 5, 2013 One thing you might consider doing (after it gets to annoy you enough) is to remove the top plate and reinstall it so that the filler plug is facing the front of the truck away from the firewall. Makes adding fluid a lot easier. Operationally it makes no difference. Nice score on the Amazon pricing! Hank Quote
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