Draining Powermaster..

[TURBOV8R]

Have the car laid up for maintenance,and actually jazzed about finding that my rear seal was NOT the culprit for leaks! Sooo,I decided to tackle re-packing the wheel bearings and draining out the brake fluid to try to keep that God forsaken powermaster going as long as it can.On other cars I would gravity bleed them out,In your opinions is this an acceptable way for this monstrosity? Also what is the pedal pumping procedure that is mentioned?I haven't had to top off the fluid yet so it's a first for even cracking the lid off the reservoir.Any tips/advice would be great.

 

[meanchicken]

I did it using a mighty vac.

First I pumped down the system....power off, pump the brake peddle to it's max at least 20 times...I go 30 for extra measure. this moves the fluid out of the actuator ball.

Then I mighty vac'd the reservior dry, and wiped it clean of all the gunk that had built up in it over time.
Then I filled it back up with my favorite fluid.
Then I mighty vac'd from each wheel cylinder nipples until I was drawing only clean, air free brake fluid at the cylinder I was pumping and kept backfilling at the reservoir to avoid sucking air in... moving from passenger rear, driver rear, passenger front, driver front

Make sure that with the system fully pumped down, you do not have more fluid in the reservoir than the max limit line in each side. Otherwise you'll end up blowing fluid out all over the place as soon power up the system and apply the brakes.

 

[TURBOV8R]

Ok,cool so it's imperative to pump the system down before removing the lid?And if so this also applies to times where you would have to add fluid I assume.Normally I use a DOT 3 fluid,don't need to use anything fancy like synthetic or anything like that or any recommendations?

 

[meanchicken]

You don't have to pump it down before removing the lid...but you should leave the lid on while pumping down, and do not add fluid before you pump it down or you could overfill and and up with a mess.


Also be careful not to get any fluid onto you paint...it'll leave a fade mark.

I use the synthetic DOT 4 stuff, but any DOT 3 for disk brake systems should be fine per the owners manual. Just don't use old fluid that's been sitting in an unsealed container for any length of time.

 

[A2000RICH]

Have the car laid up for maintenance,and actually jazzed about finding that my rear seal was NOT the culprit for leaks! Sooo,I decided to tackle re-packing the wheel bearings and draining out the brake fluid to try to keep that God forsaken powermaster going as long as it can.On other cars I would gravity bleed them out,In your opinions is this an acceptable way for this monstrosity? Also what is the pedal pumping procedure that is mentioned?I haven't had to top off the fluid yet so it's a first for even cracking the lid off the reservoir.Any tips/advice would be great.

keep life simple-----heres how to do it the easy way--------turn ignition off------pump pedal fully 10 times-------remove cover and take a turkey baster and remove the fluid from all three chambers----------replace it with dot 3 or 4-------do not use dot 5 synthetic because it will ruin the EPDM seals in the powermaster--------fill all three chambers to the marks that bring them to nearly full-------look close and you should see them--------replace the cap-----note: put the rubber gasket on the lid before putting it back on-------don't try to put it on the reservoir first--------turn the ingition on and watch the fluid level on the passenger side (inner most long chamber)-------it should drop to within about 1/4 of the bottom and stay there, you don't want it to empty completely-------add fluid if it goes too close to empty but not enough for the level to exceed 1/4 to 3/8 inch when it is pumped down-------the fluid from this chamber is stored in the accumulator and it needs to be able to go back to the reservoir if need be--------this simple two minute procedure doesn't remove all the fluid but it does change 80% of it and if you do this twice a year ( or each time you change your oil like i do) you will be covered-------it also eliminates all possibility of allowing air to enter the system that can happen if you to to the needless trouble to try to drain the lines as well--------normal operation will cause an exchange between the reservoir and the lines and regular changing will do all that is needed...............RC

 

[BILL HAINES]

Rich, John Drained My System,heck Must Have Been A Year Or So Ago. Car Will Be Ready For Spring.. Guess It Would Not Be A Bad Idea To Change The Fluid Again..(even Though It Has Not Been Driven Much,only A Scream Around Town Now And Then)my Powermaster Had Been Replaced Just Prior To Me Purchasing It. A Gm Dealer In Philly Installed A New Gm Unit(9,000 Miles Prior ) Hope It Has A Long Like Ahead...

 

[Jerryl]

TTT

 

[BobbyBuick]

Exactly,i just fixed two nonworking powermasters on cars that were setting and wouldnt cycle off doing this procedure!

keep life simple-----heres how to do it the easy way--------turn ignition off------pump pedal fully 10 times-------remove cover and take a turkey baster and remove the fluid from all three chambers----------replace it with dot 3 or 4-------do not use dot 5 synthetic because it will ruin the epdm seals in the powermaster--------fill all three chambers to the marks that bring them to nearly full-------look close and you should see them--------replace the cap-----note: Put the rubber gasket on the lid before putting it back on-------don't try to put it on the reservoir first--------turn the ingition on and watch the fluid level on the passenger side (inner most long chamber)-------it should drop to within about 1/4 of the bottom and stay there, you don't want it to empty completely-------add fluid if it goes too close to empty but not enough for the level to exceed 1/4 to 3/8 inch when it is pumped down-------the fluid from this chamber is stored in the accumulator and it needs to be able to go back to the reservoir if need be--------this simple two minute procedure doesn't remove all the fluid but it does change 80% of it and if you do this twice a year ( or each time you change your oil like i do) you will be covered-------it also eliminates all possibility of allowing air to enter the system that can happen if you to to the needless trouble to try to drain the lines as well--------normal operation will cause an exchange between the reservoir and the lines and regular changing will do all that is needed...............rc

 

[Chris Robertson]

How did you repair them? Mine looks dirty and needs fluid changed. It just keeps running. Fluid is black. New unit but car has been stored last 2 years now this is happening.

 

[Pronto]

Give that fluid flush a whirl and see what happens.

 

[BEATAV8]

For several years now I’ve been depressurizing the powermaster when I park the car and I know it’s going to be parked for a day or more. I think depressurizing it while it’s parked is much easier on the whole system and helps it to live much longer compared to letting it sit there with 700 or 800 psi stored up in it.

And change the fluid at least once a year

 

[A2000RICH]

How did you repair them? Mine looks dirty and needs fluid changed. It just keeps running. Fluid is black. New unit but car has been stored last 2 years now this is happening.

if your motor is running constantly that means that the check valve is not holding pressure or the power piston is leaking fluid back into the reservoir...........whatever do not continue to let it run or your motor/pump will absolutely fail and you will be facing a expensive bill to have it repaired