Brake bleeding issues

[Luckydog32]

My powermaster motor failed probably due to not being used in 10 plus years and moisture. I replaced entire unit with a vacuume set up out of a 88 Monte Carlo. Completely re built rear brakes with new wheel cylinders. Tried to bleed with a vacuume bleader and no success. Disconnected brake lines from wheel cylinders and tried pushing the peddle to see if I could get fluid to come out. Nothing would come out and peddle was rock hard. Took proportion valve out and cleaned out with brake cleaner. Reassembled and nothing. Before attaching brake lines I blew rear lines out with compressed air to make sure they weren’t blocked or crushed. Any other thing I should check!

 

[Jerryl]

Did you change the brake pedal?

 

[Luckydog32]

Yes. Pedal, booster, master cylinder all changed. If I disconnect brake lines at the master and press the petal it squirts fluid out.

 

[Jerryl]

Bench bleed?

 

[Luckydog32]

Bench bleed?

I will try that when I get home this evening.

 

[Jerryl]

If you look in the bowl, you will see the small holes for the fluid to get into the cylinder. Verify that the rubber cups are past the holes towards on the firewall when the pedal is released, so fluid can get to the cylinder. Bench bleed and reinstall but don't pump and release with outlet ports open to air as it will suck air back into the master. Let us know what you find.

 

[Luckydog32]

If you look in the bowl, you will see the small holes for the fluid to get into the cylinder. Verify that the rubber cups are past the holes towards on the firewall when the pedal is released, so fluid can get to the cylinder. Bench bleed and reinstall but don't pump and release with outlet ports open to air as it will suck air back into the master. Let us know what you find.

Will do thank you.

 

[Luckydog32]

If you look in the bowl, you will see the small holes for the fluid to get into the cylinder. Verify that the rubber cups are past the holes towards on the firewall when the pedal is released, so fluid can get to the cylinder. Bench bleed and reinstall but don't pump and release with outlet ports open to air as it will suck air back into the master. Let us know what you find.

Still no luck going to replace master cylinder and proportion valve. Hopefully this does the trick.

 

[Jerryl]

Still no luck going to replace master cylinder and proportion valve. Hopefully this does the trick.

I recently had 3 defective master cylinder's in a row. One was ACDelco NOS and 2 rebuild. Chased my tail and ended up with a wildwood.

Pic is of a rebuild unit, while bench bleeding. Notice the dirt.

 

[Luckydog32]

Changed master and prop valve. Have softer pedal than before but still won’t bleed. Front brakes have good fluid pressure. Back just trickles out( which is more than I got with other master). I’m about at my wits end with this. Going to get a better vacuume bleeder set up tomorrow.

 

[TRICKSIXPA]

Same problem I’m having with my car but I got the system to finally bleed. Bled the system start the car and pedal goes to the floor! Seems like I’m getting air in the master cylinder!


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[turbofrank]

An old wise man once told me never buy reman master cylinder. After buying 3 for my Honda lesson learned.

 

[Luckydog32]

Update on bleeding brake issue. Finally got a good pedal after hours of bleeding. What I ended up doing is. Bench bled new master cylinder and installed. Made a “ pig tail” for the rear brake hole on the proportion valve and bled system from master through proportion valve. This took about 10- 15 min using a mighty vac. Once I got no air bubbles I reconnected rear brake line. Started with passenger side rear then went to driver side rear. Once I sucked out all the air I went back to passenger side rear and bled brakes by pumping brakes with a helper. I will say most of my air problem was coming from the connection on the mighty vac. I just took some safety wire and made a clamp to seal up the leak.

 

[TexasT]

I think you are way better off to try to bleed the old fashion way, open the bleeder with a hose on it and a clear catch container so you can see the bubbles and when just fluid comes out, helper applies pedal slowly with a block of wood under the pedal to prevent over stroking the master cylinder, close the bleeder, and repeat until clean, clear fluid comes out, then move to the driver rear. and repeat. Keep the master full or you get to start over. Those vacuum things dont exert the force on the lines to push the rust and crap out.

After mine sat I had to keep taking the bleeders out to clean the crap out of it when we bled it. Upside of this is there is new fluid throughout the system and you get to make sure by seeing the old stuff come out.

 

[TurboSlacker]

I think you are way better off to try to bleed the old fashion way, open the bleeder with a hose on it and a clear catch container so you can see the bubbles and when just fluid comes out, helper applies pedal slowly with a block of wood under the pedal to prevent over stroking the master cylinder, close the bleeder, and repeat until clean, clear fluid comes out, then move to the driver rear. and repeat. Keep the master full or you get to start over. Those vacuum things dont exert the force on the lines to push the rust and crap out.

After mine sat I had to keep taking the bleeders out to clean the crap out of it when we bled it. Upside of this is there is new fluid throughout the system and you get to make sure by seeing the old stuff come out.

I second this method.

Have struggled many times trying to bleed my GN brakes whenever I changed parts or regular maintenance. The vacuum system and the power bleeder top end pushing style never got all the air out. Simple and patient manual style worked the best for me. Key is having a buddy pushing on the brake pedal while you bleed at the wheel bleeder.

My 9 year old has that buddy role down pat now LOL.

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