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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: fabioblazer on April 09, 2009, 01:04:55 pm

Title: k5 brakes problem
Post by: fabioblazer on April 09, 2009, 01:04:55 pm: hello guys!

i replaced pads and front flexible hoses to my '81 k5 Blazer, cleaning old oil everywhere and replaced with new one.

after replacing parts i bleeded the system but unluckly the right rear wheel screw is blocked
the problem is that now brake pedal travels to the floor almost completly and blazer doesn't brake!

can you help me please?
thank you very much!

Fabio
Title: Re: k5 brakes problem
Post by: choptop on April 09, 2009, 07:15:34 pm: You either still have air in the system in the lines or the master cylinder itself, or your master cylinder is bad. That one bleeder not comeing out can cause problems on that wheel. Definately sounds like air in the system. Once you replace lines like that, it take a while to get all the air out.
Title: Re: k5 brakes problem
Post by: VileZambonie on April 09, 2009, 10:09:21 pm: What do you mean the wheel screw is blocked? Do you mean you can't to the bleeder screw? Do you mean no fluid comes out?

Quote
cleaning old oil everywhere and replaced with new one.

What do you mean by this?
Title: Re: k5 brakes problem
Post by: fabioblazer on April 10, 2009, 04:56:40 am: i mean that the bleeder RR is blocked and i have not new one, so before force it i think it's better to get new one.

i hope that problem is just this, 'cause before replacing pads and flexible hoses, there weren't problem.

i disconnected hoses from master cylinder too, to clean all system, surely air comes in circuit.

i realize a strange thing...when i push down brake pedal, reservoir assembly rises up from master cylinder.
not enough to disconnect itself but enough to seem a strange thing.
Title: Re: k5 brakes problem
Post by: choptop on April 10, 2009, 06:26:18 am: If you can remove the rr bleeder, you can clean it out very easily. I just run a drill bit, by hand not with a drill, and twist it in through the top, then through the side. Clean it out with sone air and put it back it. If you can get it outm the rest is easy. The master cylinder rising does concern me. Is it the whloe booster, or just the reservor itself. Is it the plastic tank or the one peice cast iron master cylinder?
Title: Re: k5 brakes problem
Post by: fabioblazer on April 10, 2009, 10:04:42 am: ehy chop!
the reservoir is divided into two parts front and back with 2 hoses, it's a plastic tank and just the back part rises.
Title: Re: k5 brakes problem
Post by: fabioblazer on April 10, 2009, 12:05:01 pm: ehy friends! bleeder released!

finally! air and so much s**t from hole!

actualy brake pedal runs better but i think there still is too much lash.

then i saw that when plastic reservoir assembly rises, some oil comes out of the gasket that holds it connected to the master cylinder.

ehy thanks again for help!
Title: Re: k5 brakes problem
Post by: joesgarage71 on April 10, 2009, 02:04:40 pm: I'd be getting a new master cylinder if its leaking fluid out its leaking air in.
Title: Re: k5 brakes problem
Post by: fabioblazer on April 11, 2009, 05:17:41 am: do you think so?

i don't understand why reservoir assembly rises a little when i push down brake pedal...
it means oil doesn't run into circuit right?

the problem is to know if cause is in the master cylinder (maybe one of 2 little pistons is blocked) or in the circuit (but actualy oil comes out good from all 4 bleeders)