Powermaster fluid flush problems

[DOUGGN]

Decided to change out the old dirty fluid in the PM today. read zeus87gn's sticky on "how to". My PM was working fine prior to this. I opened up the fluid res. and sucked out 1/2 of the fluid. I pumped down the accumulator with more than 10 pedal cycles. The pedal really never got "hard to press". I then sucked out the rest of the fluid, wiped out the res. and filled up about 1/2 way with new dot 4 fluid. Turned on the ign. and the PM pumped back up to pressure. At this point I would think it should still operate like normal - instead the pedal goes about 3 inches and is very soft. Does anyone know what I did wrong? I guess this is where the statement "if it ain't broke - don't fix it" comes in.

 

[87GNSteve]

Might have gotten air in they system.

 

[DOUGGN]

I did not pump anything while I swapped the fluid - where would air have entered the system? If air did enter somehow -would that mean I would have to bleed the master cylinder and the wheels or just the wheels?

 

[chopped39]

I did not pump anything while I swapped the fluid - where would air have entered the system? If air did enter somehow -would that mean I would have to bleed the master cylinder and the wheels or just the wheels?

Bleed the master first and then the wheels

 

[TurboDave]

When you filled the reservoir as you said "1/2 full", and turned the key on, DID YOU WATCH THE LEVEL GO DOWN and make sure it didn't get sucked empty????

If you emptied the reservoir, and only filled it half full before turning the key on, that's a definate problem!!! It likely sucked that half full down to nothing and got air in it then.

 

[turbodave231]

I do this all the time and I've never had any problems.

The reservoir is divided into three sections. The section on the inboard side toward the engine supplies the EH pump and only the pump. When the system is pressurized, It normally appears very low. When the system is de-pressurized, that section of the reservoir should appear full. When the diaphram inside the accumulator goes bad you will see very little change in level between pressurized and depressurized. You can depressurize the system with the key off and watch the level change when you turn the key on.

You most likely got air. Bleed the systems and report back.

 

[DOUGGN]

I do this all the time and I've never had any problems.

The reservoir is divided into three sections. The section on the inboard side toward the engine supplies the EH pump and only the pump. When the system is pressurized, It normally appears very low. When the system is de-pressurized, that section of the reservoir should appear full. When the diaphram inside the accumulator goes bad you will see very little change in level between pressurized and depressurized. You can depressurize the system with the key off and watch the level change when you turn the key on.

You most likely got air. Bleed the systems and report back.

I bled the master cylinder and then re-bled the 4 wheels. Pumped up the PM and filled everything back to the proper levels. Started the car, pumped the pedal a few times and it seems to be back to normal. Just backed it back and forth in the driveway a few times to test it out. The weather is rainy right now so I will wait to drive it on a better day. Thanks for the help everyone!:biggrin:

 

[zeus87gn]

Doug,
Just sent you a PM.
I'm glad to see you got it back into shape.
Let us know if it works well under normal conditions.