Bleeding Brakesm problem

[turk1955]

Ok so got a problem, my 55 210 has disks up front and drums back I found a bad spot in the line leading back to the rear and replaced the bad section also found one bad wheel cylinder driver side rear and replaced that so my next I got a friend to help bleed the rear system. Hear is my problem, after going through the bleeding process (person in car pumps pedal 3 times then holds it down then I open bleeder to let air out then close it then he would release pedal ) this we did and I have gone through at least a quart and still getting air !! We have checked all the fittings and found nothing, what the heck I am missing ??? FYI: this car is equipped with a booster and proportioning valve but I don't think that has anything to do with the problem, any help would be greatly appreciated. 9469

[Gmvette]

I suggest to start off bench bleed the master cylinder first. This can be done in the car. There are many you tubes on this topic. If the master cylinder is new that does not pardon it from defects. It is quite common to open a box to discover the master cylinder is JUNK.

If the bleeding goes good then start gravity bleed with all 4 bleeders open till dripping occurs at all them.
Then get buddy to assist on the brake pedal and drain till no air comes out each wheel.

[turk1955]

Ok but before I do that I have a question, this setup was on the car when I bought it and all was good till just about a month ago when I noted it started pulling a little to the left and on inspection I found the driver side rear wheel cylinder was leaking so I replaced it also found a spot on the line leading back to the rear so replaced about 3' of the line. This is the only changes that where made so y should I have to bleed the master cylinder or the front brakes?

[markm]

You should always replace wheel cylinders and calipers in pairs.

[turk1955]

Ok forgot to mention that I did replace both rear wheel cylinders

[Gmvette]

If you have no leaks anywhere the and still no pedal the master cylinder has gone south. But unless all the air is out of the system you don’t know for sure. Do you have a vacuum pump to apply negative pressure at each bleeder screw? It is a positive way to insure solid fluid and no air. I do that on every brake job after gravity bleeding.

[Rick_L]

Are you getting a decent amount of fluid out of the bleeders when bleeding? Are you sure that the shuttle in the combination valve hasn't closed the rear brakes off?

I know you said you went through a quart of fluid, but just checkin'.

[markm]

Are you getting a decent amount of fluid out of the bleeders when bleeding? Are you sure that the shuttle in the combination valve hasn't closed the rear brakes off?

I know you said you went through a quart of fluid, but just checkin'.


I have experienced this one or a collapsed rear hose.

[turk1955]

Ok so today I spent at least 4hrs gravity bleeding the rear brakes and at first the pedal felt great so I had the wife get in and do the pedal while I opened the far bleeder just to make sure all the air was out well after the 2nd try the dam thing started pushing air again and pedal went soft again, this is getting irritating !!

[kbuhagiar]

Ok so today I spent at least 4hrs gravity bleeding the rear brakes and at first the pedal felt great so I had the wife get in and do the pedal while I opened the far bleeder just to make sure all the air was out well after the 2nd try the dam thing started pushing air again and pedal went soft again, this is getting irritating !!

Not trying to state the obvious, but are you making sure that the MC reservoir stays full while bleeding?

[55 Rescue Dog]

If you haven't overlooked something else, I would also say the master is bad, which can happen when you push it full stroke and it tears a seal in the seldom used part of the bore on a used cylinder. Also, I have found the best way ever to bleed a whole dry brake system by yourself in less than 30 minutes is to use an air powered vacuum bleeder like the one OTC sells. It's a lifesaver I've successfully used many times now on a completely empty brake system, and makes the $100 I spent on it a bargain. Just pull the trigger and watch it flow, and don't worry about the bubbles being pulled in around the bleeder threads. It's all about filling the lines with fluid quickly. Don't need to bench bleed the master either. I've learned brake bleeding the hard way too many times before. You can also just stand up a bottle of brake fluid in the reservoir, and make it auto-refill as you go. Just recently did this bleeding the all new brake system on my 1950 1.5 ton, but just added a short piece of hose to the nozzle of the bottle to reach the reservoir under the floorboard. Bled the whole system with 1 quart by myself in no time. I also use the vac bleeder to occasionally empty, and refill master reservoirs to keep the fluid fresher instead of doing what I should, a 2 year flush on all of my vehicles. Brake fluid loves to suck up water, and ruin your brake system.

[turk1955]

yep

[turk1955]

You by chance have a part # for that OTC bleeder

[Rick_L]

which can happen when you push it full stroke and it tears a seal in the seldom used part of the bore on a used cylinder.

I'm going to speculate that RD has nailed the problem. This is supported by your statement that the fluid stream seems to be momentarily bubble free but has bubbles when you bleed again. And perhaps why the master cylinder is a problem now but wasn't the original problem.

[55 Rescue Dog]

You by chance have a part # for that OTC bleeder
This is a newer version of the one that I have. You can get the auto-refill bottle for another $43 which would be nice to have, but easy to replicate. In my 1950 truck manual they actually show using something similar to keep the reservoir filled while bleeding.
https://www.amazon.com/OTC-Equipment-Vacuum-Bleeder-OTC-8104A/dp/B075QPDZ3S/ref=sr_1_6?ie=UTF8&qid=1547035696&sr=8-6&keywords=otc+vacuum+brake+bleeder

[turk1955]

yes

[markm]

I'm going to speculate that RD has nailed the problem. This is supported by your statement that the fluid stream seems to be momentarily bubble free but has bubbles when you bleed again. And perhaps why the master cylinder is a problem now but wasn't the original problem.

I too have experienced this and one I bit the bullet and bought a MC life was good again.

[kbuhagiar]

Since we are talking brake bleeding systems, this is the one (Motive Power) I've used successfully for around 20 years:

https://www.summitracing.com/parts/mvp-0105?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-motive-products&gclid=Cj0KCQiA1NbhBRCBARIsAKOTmUs6wn1v091oSFfvWlcw TMR74EfmabueiJI6unu75n5Aj9OdX687V2gaAj57EALw_wcB

Nice and simple. Do it once and you're done.

[56Safari]

Since we are talking brake bleeding systems, this is the one (Motive Power) I've used successfully for around 20 years:

https://www.summitracing.com/parts/mvp-0105?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-motive-products&gclid=Cj0KCQiA1NbhBRCBARIsAKOTmUs6wn1v091oSFfvWlcw TMR74EfmabueiJI6unu75n5Aj9OdX687V2gaAj57EALw_wcB

Nice and simple. Do it once and you're done.


I second this, I made my one man bleeder out of an old garden sprayer instead of buying one but they work really well. So much better than trying to find somebody to help.