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I was changing out the brake fluid in my very low mileage 73-98, it was very dirty and brakes not working well low pedal. Fronts bled out nice but I can get very little fluid coming out of the back bleeders when trying to bleed them. I believe the problem is in the distribution block? But i don't know if it just has to be reset somehow ? or rebuilt or replaced?
Any help would be appreciated
Thanks Greg
Seems I remember there's a button on the distributor block that has to be depressed to help flush brakes. Shop books made a big deal about the special tool needed to do the job. This is from 76 CSM but I've seen it in all 70s shop books.
Seems I remember there's a button on the distributor block that has to be depressed to help flush brakes. Shop books made a big deal about the special tool needed to do the job. This is from 76 CSM but I've seen it in all 70s shop books.
I did see that in the manual but it said that needed to be done to bled the front brakes and those bled out fine?
Maybe crack the line at the master cylinder to make sure there is pressure in the rear line. Could be the master cylinder is leaking internally.
I have bench bled and replaced the master cylinder and both rear wheel cylinders, i get a little air and some fluid when i pump it but i never see the rear brakes move when pumping them.
Those rubber hoses can really play tricks on you. I remember years ago on a 72 Cutlass Supreme I had. The left front wheel would keep locking up. The rubber brake hose acted like a check valve in that it would let fluid through it but not back out. When you applied the brakes it would not release afterwards. Like to have driven me crazy. It was kind of the exact opposite problem from what you are having. It would be a good idea to replace all the hoses on a car that is almost 50 years old.
Is the brake light on at your dash with Ebrake released? Is the wire connected to the distribution block? Remove the wire from the block and ground it with the key on, does the dash light come on? If the answer is no to light, yes to the wire connected, and yes the light comes on grounding the wire, then I'd say there is a really good chance it's the hose.
At the 2017 Olds Nationals, the guest speaker had lots of stories to tell and one was how to bleed the rear brakes with a dual master cylinder. Let the front brakes run dry, bleed the rears, then refill and bleed the fronts. The idea is that the front brakes will engage and not let the brake plunger move far enough to force the air out of the rears. Using a power bleeder might help so you wouldn't be using the pedal to supply pressure to the brakes for bleeding.
At the 2017 Olds Nationals, the guest speaker had lots of stories to tell and one was how to bleed the rear brakes with a dual master cylinder. Let the front brakes run dry, bleed the rears, then refill and bleed the fronts. The idea is that the front brakes will engage and not let the brake plunger move far enough to force the air out of the rears. Using a power bleeder might help so you wouldn't be using the pedal to supply pressure to the brakes for bleeding.
The guest speaker apparently does not know how to work on brakes. Follow this advice and you'll be screwing around for hours with a multitude of self inflicted problems.
The guest speaker apparently does not know how to work on brakes. Follow this advice and you'll be screwing around for hours with a multitude of self inflicted problems.
I think Bob Brannan might know a thing or two about how to work on Oldsmobiles being a Zone Service Director for Oldsmobile back in the 60's to 80's. Just sayin...
Well I got the rear flexible line off on the brakes and it was clear as a bell, in fact I removed the old one and no fluid came out anywhere? Guess I am still thinking that the metering valve on the front of the frame needs resetting, repairing, or replaced. That's the only thing between the new master cylinder and the rear brakes that I haven't touched? Anyone dealt with this thing before?
Also what is the secret of getting that hex end of the rear brake like back through the frame its like a puzzle no matter which way I turn it it wont go back in?
It's a long shot, but it could also be internal rot in the steel line. Loosen that line at the front where it goes into the combination valve (aka distribution block) and press the brakes. See if fluid squirts out. If it does, it's the line. If it doesn't it's either the combination valve (could just need recentering) or the master. You can check the master by loosening the line from the master into the combination valve (the line closest to the one that goes to the rear).
and the shuttle has stuck at one end or the other you will probably need to take it apart and re-center it. I just went through this with my brakes. Mine came with a plastic screw-in button to keep it centered while working on or bleeding the brakes and I didn't use it. My front brakes wouldn't bleed so they didn't work. A quick Google will find the closest place where you can get one. There are fittings on both ends that can be unscrewed so you can move the shuttle which ever way it needs to go. It should move fairly smooth, it is suspended in the bore with o-rings on each end. You don't need to remove the shuttle to see when it is centered, unscrew the warning switch, it is dry, and you can see when the low spot is centered and install the centering button. Mine was too far to one end to catch the shoulder of the low spot so i had to take the ends off and center the shuttle. Bleed your brakes and re-install the warning switch and you should be good to go. Remember to bleed the fronts last.
Just wanted to put a end to this thread as the brakes are now bled and working great. Kept thinking problem was in the proportioning valve since I couldn’t get fluid past there I took it off and it was in the center and I put that thing in the top to keep it from moving but still wouldn’t bleed. I sent the valve out to have it rebuilt it came back and I put it in and same results. It finally dawned on me that I had a vac tool used for checking diaphragms and it said it was also used for brakes so I put that on pumped about 5 or 6 times and started getting fluid out then did the other side same way then just bled the brakes like normal in 20 min I was done which is how it should have worked in the first place. Hope it helps someone else out down the line
Greg, you used your hand operated vacuum pump to "suck" brake fluid to the rear brakes via. the bleeder screws? Just want to make sure I understand...
Yes the kit had a bleeder attachment and I used the tool to suck the fluid to the rear cylinders on both sides once I did that they bled normally. I still in my head dont understand why the brake pedal wouldn’t have done the same thing pushing the fluid back? Been a 4 week nightmare trying to figure it out in my spare time and the part I sent out got lost for a week too lol
I think Bob Brannan might know a thing or two about how to work on Oldsmobiles being a Zone Service Director for Oldsmobile back in the 60's to 80's. Just sayin...
By the way, I know Bob and respect his knowledge. However I believe you may have misunderstood what he might have said. Running the master dry with it being mounted at an angle is not going to end well for rebleeding in place with a large air pocket in it. We bench bleed master cylinders for a reason.
By the way, I know Bob and respect his knowledge. However I believe you may have misunderstood what he might have said. Running the master dry with it being mounted at an angle is not going to end well for rebleeding in place with a large air pocket in it. We bench bleed master cylinders for a reason.
I didn’t make a comment on that I think someone else did
By the way, I know Bob and respect his knowledge. However I believe you may have misunderstood what he might have said. Running the master dry with it being mounted at an angle is not going to end well for rebleeding in place with a large air pocket in it. We bench bleed master cylinders for a reason.
