Another brake thread.

[Ryhz]

So I’m late to the party I see with this post but I wanted to give my two cents anyways…first I’d like to say great job on the fronts they look way better. Good decision with the booster but I’m not sure I saw if you replaced the master also? That’s probably the first thing I would have replaced. The next thing is I’m betting the rear lines have collapsed plus you have frozen wheel cylinders. I’ve run into that issue multiple times where I can’t bleed them because the cylinders are rusted frozen in place. I ran into that issue recently with mine but the bleeder valve snapped off in the process so I’m going to be replacing everything for the rears including the e-brake lines and if I can’t resurface the drums I’ll get new ones as well. You definitely should get a helper to bleed everything it makes the process so much easier

Much thanks. I replaced master cylinder and booster. New bleeders all around since the fronts were clogged. The rear rubber line was collapsed/blocked inside so I replaced that as well.

I figured if the back rubber line was bad, it was only a matter of time until the front rubber lines would be bad. So I started that, but trying to get those disconnected inside the frame is a pain. Once I finish that job, I will bleed all 4, and reassess where I'm at. I really hope I don't have to tackle the wheel cylinders this time.

 

[AZ Highlander]

@Rhyz , I currently have my front brakes actually seizing up when I drive far/fast enough. I am pretty sure its the hoses collapzing/delaminating inside as well. After researching the brake hose replacement procedure, I watched/read that many guys will cut/grind off the connection hardware that goes through the frame since its such a pain and all of it will be replaced with new fittings/connection hardware anyway. Not sure if that is your plan, but thought I would mention it since it could help get them out.

 

[chrischobo]

First, I've got a 73 c20. It's 8lug, with discs in front, and drums in the rear. I've been at it all day. I bought the truck and knew there was a brake issue but the previous owner didn't know what was wrong. Brake pedal goes all the way to the floor. The first half its easy, then the second half it's hard like I'm doing a leg press. It barely stops.. BARELY
I'm also getting no fluid to the rear brakes.
I've bled brakes (passenger rear, driver rear, passenger driver, front driver) using the two person system. I've done a tube in a bottle until no more bubbles, and borrowed a vacuum bleeder. No change.
I used a master cylinder bleeder kit to bleed it. Ran lines returning to the fluid back to reservoir, and pumped until no more air.
Blocked the master cylinder off and blocked the 2 outlets. Pumped, and built pressure (only time I've got pressure). I opened one outlet, and the pressure escaped. Tried the other outlet, and same.
I disconnected the rear brake line from the proportioning valve. I ran air from the front of that, and went to the rear. No air, no bubbles, nothing, so I'm believing an issue or clog somewhere along the line?

I also ran fluid into the lines I disconnected from master cylinder and fluid runs out of the proportioning valve.
I don't know what more to do. At this point I'm thinking replace master, booster, and lines. I just didn't want to throw money at it if I could find the issue/issues. Thanks for all the help

If the brake lines are old then most likely the rubber has swelled up.to the point of.stopping flow.

 

[Ryhz]

If the brake lines are old then most likely the rubber has swelled up.to the point of.stopping flow.

Yup, this is correct. The rear one was completely blocking fluid. I'm getting fluid to the front, but replacing them as well.

 

[Ken B]

Having brake fun too.
I think the pedal is the only part not replaced.
Just did wheel cylinders on rear. Last brake line (steel) just wants to fight being threaded into cylinders. Maybe its the fact that my old eyes can't see ****

 

[Ken B]

It's confirmed my new proportioning valve works. Had the bleeder tool screwed into prop valve to hold it. Thought pressure was somewhat equal. WRONG. Unscrewed tool and I heard the valve shift and shut off back brakes....2 steps back...but know it works

 

[Ryhz]

Late Update:

Got busy with other things, but got some free time today. I ordered a 3/8 flex flare wrench, and it made getting the drive rubber hose off a piece of cake. Now that I all 3 rubber lines have been replaced I went around and bled the system twice. I can now say I have brakes. I feel safe getting to highway speeds and stopping suddenly.

I'd still like to improve them, . I drive an 89 caprice every once in a while and they are close to that. Definitely no where near my 95 toyota daily beater or new car. I'm not sure if this is just what 73 brakes feel like or I have room to improve them. (does upgrading to 2 piston calipers make any difference?)