03 YXL DENALI JH2, JL4, Z55 BRAKE BOOSTER REPLACEMENT

[djm3000]

160K and have done some heavy trailering short distances tailgaiting in 100degree weather in Austin, TX in the last 6 years.

 

Current situation is there is a power steering fluid leak between the brake master cylinder and the brake booster unit behind the bracket.

 

Had a mechanic replace the low pressure and high pressure steering lines.

 

Questions:

1. Is this the right part?

ACDELCO Part # 1780685 {#15854058} Reman

BOOSTER,P/B w/7200# PWR BRAKES(JH2)

 

2. Are there any other parts?

 

3. Can I just unbolt the Brake Master Cylinder from the Power Booster - will the Brake System retain pressure or will I have to bleed afterwards?

 

4. If I get the BMS off, is there just a seal, o-ring, etc that I can replace without taking off the Power Booster?

 

5. Is there a flush or bleed that I have to do to the power steering system?

 

6. Anything else?

 

Thanks,

 

Dave

 

 

 

 

 

[jmpidgeo]

1 and 2 I do not know

 

3: you should be able to unbolt the master cylinder without having to re-bleed. I'm not sure if you'll be able to move the master out of the way without having to disconnect the lines though.

 

4: in my experience there is not a seal there, between the two units, but I've never replaced a hydroboost unit on my own. Sounds to me like a seal inside the booster has worn out.

 

5: when I changed my power steering pump, the bleeding procedure was simply turning the wheels lock to lock to bleed the air out. I would assume that pumping the brakes would come into the equation somewhere with hydroboost, but I am not sure.

 

Hopefully that helped at least a little bit until some real technician or someone with more experience chimes in.

[Duelin]

Sit back and watch. It is not exact but simular.

 

 

[djm3000]

Thank you jmpidgeo and Duelin!!

 

Am going to try this weekend.

 

I have replaced the water pump and steering gear on the vehicle. Is the degree of difficulty (and getting it right) really 8/10 like my mechanic said? He is a former aircraft mechanic and does excellent work and I trust him. Is there more to it than unbolting, reconnecting, bleeding?

 

Thanks again!!