No Brake Pressure - HELP
Thread Starter
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Joined: Sep 2016
Posts: 89
Likes: 2
From: Mobile Alabama
No Brake Pressure - HELP
Ok so I have replaced the entire brake system on my 79 project. New Booster, M/C, All new brake lines including all rubber lines, new proporioning valve, New calipers etc... The calipers are reman lifetime warranty with lip seals not o-rings. I have bled the system over and over. I bled the M/C on the bench twice and no more air, I have tried gravity bleed, vacuum bleed, Standard 2 person bleed, reverse bled and it looks like all the air is out. No matter how much I bleed the system, the pedal continues to go the floor. I replaced the M/C a second time thinking it was bad, but same issue. I plugged the M/C outlet lines and the pedal is solild so the issue is somewhere in the lines. There are no visible leaks anywhere. I am at a loss as to what is goin on and what to check and how to correct this. Any thoughts or suggestions. I'm about to the point of trying to plug every line at the caliper and see if its solid and go one by one unless there's a better way. Seems like I've spend way too many hours on this what should be a simple task.
Burning Brakes
Joined: Oct 2006
Posts: 1,006
Likes: 28
From: Lutz Florida
After you bled the brakes and had no change in pedal was there air in the lines when you tried bleeding them again? If so then air is getting in somewhere. One place could be the bleeders themselves. It is possible the bleeders are drawing air back in to the system when cracked open. I had a heck of a time trying to bleed my brakes using a Mity-Vac. When I cracked the bleeders the vacuum draw from the Mity Vac pulled air in from around the threads of the open bleeder. I solved it by sealing around the bleeder with Vaseline before cracking it open. It worked. What worked better was a Motive brake bleeder. It pushes the fluid with a constant pressure outward. It was worth the money for the aggravation it saved.
The only other thing I can think of is the booster rod. Check to make sure you have the correct length set for your booster/master cylinder combo.. Depending on the booster, some come with a fixed long rod and a fixed short rod and some come with an adjustable rod.
Hopefully someone else may have more ideas but since everything is new that about all I could guess.
I know its frustrating but stick with it. you'll get it fixed.
The only other thing I can think of is the booster rod. Check to make sure you have the correct length set for your booster/master cylinder combo.. Depending on the booster, some come with a fixed long rod and a fixed short rod and some come with an adjustable rod.
Hopefully someone else may have more ideas but since everything is new that about all I could guess.
I know its frustrating but stick with it. you'll get it fixed.
Thread Starter
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Joined: Sep 2016
Posts: 89
Likes: 2
From: Mobile Alabama
I tried the motive pressure bleeder but could never get s solid seal on the M/C to push the fluid through without leaking all over the place. Gave up and used a garden sprayer bottle with pressure guage on it put over the bleeder to pressure bleed in reverse back up to the M/C, actually worked very well and appeared to get all the air out but still no pressure. Would the rod still cause it to be solid when the lines are blocked off? That was one thought as well as bad M/C or Booster, but by isolating that part of the system it seemed to work perfect.
Thread Starter
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Joined: Sep 2016
Posts: 89
Likes: 2
From: Mobile Alabama
Yes. The rear has 2 per caliper and 1 per caliper up front. I'm going to plug the system at each caliper and test to find the problem line I hope and I may even add a bleeder on the rear calipers where there is a plug to try to bleed more area if all else fails.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
The only thing I can think of is the fitting or connections of the rubber hose to the front caliper. I believe only the front units get a copper washer. As I recall, that crush washer should only be installed one way. I think it was the flat side towards the caliper maybe? Round side towards the line?
Anyway, a leak at that fitting is hard to see. Black caliper, black hose, dark area under there. I had a H of time finding that leak.
Do you recall installing the crush washers? And is that area on the caliper bone dry?
Anyway, a leak at that fitting is hard to see. Black caliper, black hose, dark area under there. I had a H of time finding that leak.
Do you recall installing the crush washers? And is that area on the caliper bone dry?
Thread Starter
Advanced
Joined: Sep 2016
Posts: 89
Likes: 2
From: Mobile Alabama
Hadn't thought about that yet, I will definitely check it and see if I can tell. Have fluid all over though from bleeding so many times. May still do the method of isolating front from rear to narrow it down.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
Supposedly those crush washers are a "one time deal". But I have reused them before on my truck w/o a leak. If you pull the hoses you should install new washers. Check the threads of the brake hose real close at the front caliper. Have someone apply some pedal pumps while inspecting for seepage.
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