Hard pedal, no brakes, brake light on...

[zeus87gn]

that res vac tank u mentioned, thats just to extend the time I have brakes in the event my engine dies at high speed? or is there an issue of the vacuum thinning out when you put the car into boost?

The issue is Both.
At either time, when the engine dies or when you are in boost, you have NO vacuum.

Remember, you can ship your old P/M to Kirbans and get $100 credit towards the purchse of more stuff from him. Or $75 cash.

Or you can just ship it to me for helping you...:biggrin:

 

[MSDGN]

Just an FYI...brake light on can also be caused by the proportioning valve sticking...had that happen...I had the brake light come on...figured it was the accum...replaced that...same thing...so I decided to just rebuild the PM unit...same thing...light still on...so I unplugged the elec connector on the prop valve and...light went out...I went ahead and replaced the cast iron valve with a newer brass one...

 

[sweatnblood]

well I'm glad I'm not the only one with this prob. the 1st few times it was an easy fix with the fuze blown...I think i have electic. prob...that is going to suck...but this last time the fuze was good, but I'm not getting any juice to the fuze now...and no whinn sound from the brake booster thing...so what would you guys think that might be...and also if I want to convert the brake system...where can I find the directions and conversion kit at...thanks for your help

 

[youngstr]

Just an FYI...brake light on can also be caused by the proportioning valve sticking...had that happen...I had the brake light come on...figured it was the accum...replaced that...same thing...so I decided to just rebuild the PM unit...same thing...light still on...so I unplugged the elec connector on the prop valve and...light went out...I went ahead and replaced the cast iron valve with a newer brass one...

I'm a little confused, .....

ok, so anytime you get a hard pedal, your pump stopped (but the cause is not necessarally the pump), but could be a problem with the pressure switch, or acc, or prop valve or harness or fuse , and any of these can cause the pump not to run....or the pump is bad? Is that how the sys works?

Does that brake light trip the sys and cause it to shut down the pump?

I'm just trying to get the big picture on how this system operates.

 

[zeus87gn]

It can be a confusing system.
I think that's why so many people convert to vacuum - because it can be so confusing, and if you don't "get it" you'll forget it.

I get it, but I'm an electrical engineer in the fluids business.
You've seen this diagram: http://www.gnttype.org/techarea/images/PwrMstr.gif
It may help you understand more what makes the light come on.

The pressure switch is setup to trigger the light when the pressure is below a certain point - usually when the motor either can't keep up or just isn't working. It also turns the motor on and off at different set points - above the low pressure set point. The problem is that the low set point is usually too late.

If the pedal gets hard, the pressure in the system is too low.
It is up to the mechanic to figure out why.
1 - the pump isn't working - why?
2 - the acc is dying - time to replace?
3 - the switch is faulty - how do you determine that?
4 - the system is internally leaking - Seals or check valve?
The diagnostic tests give you time intervals.
They have to be interpreted.
There are many points to consider.

Does this answer your question?
It's a purely mechanical system.

 

[BW Jones]

well I'm glad I'm not the only one with this prob. the 1st few times it was an easy fix with the fuze blown...I think i have electic. prob...that is going to suck...but this last time the fuze was good, but I'm not getting any juice to the fuze now...and no whinn sound from the brake booster thing...so what would you guys think that might be...and also if I want to convert the brake system...where can I find the directions and conversion kit at...thanks for your help

if:
1) the brake fuse is not blown and
2) you no longer have voltage to the fuse and
3) the whining sound from the powermaster is also no longer present (because it isn't receiving voltage)
..... you must have an open circuit (burnt wire) somewhere.

Red Regal sells a complete vacuum system in the 'Parts for Sale' forum that includes installation instructions.

 

[sweatnblood]

ok great thanks so much for the insight...this should help alot and prob need to just start running down elect. prob anyway....I think I have a bad ground somewhere...

 

[youngstr]

ok

Yes that does answer my question pretty well, thank you.

There are 2 other things I've noticed

1. My fluid is pitch black like motor oil.

2. The Resevour for the brake fluid is full the the very top of the container, not sure if that is normal, on my other car that has vacuum brakes the res is full to the top of the markings on the res, but my regal seems like its too full, to the point that when I put the lid back on (not realizing that it was that full, it actually seaped out as I pressed the lid on a beautiful mess

I'm thinkin pull the powermaster out, put vacuum in, and then spend some quality time later this summer getting familiar with and rebuilding the powermaster, (isn't there a kit for doing that?)then if I sell the car (kinda doubtful being how much I like the car), I can always put it back in if needed.

 

[zeus87gn]

W/R/T your 2 points...

1 - Black fluid is a NO NO.
It doesn't matter what brake system you have.
Brake fluid is gold and translucent.

2 - Full on any fluid bowl is to the marks. I don't know if any are supposed to be full to the very top. The ps of the bowl on the P/M isn't suppoed to be full unless the acc is pumped down. When it's pumped up, the same ps of the bowl should be about half full.

Good luck on finding a rebuild kit. They have been discontinued for some time and what few are around are not cheap. If you are dead set on converting, send your old unit to Kirbans and get $100 towards the purchase of anything in thier catalog or $75 cash. Kirbans will sent it off to Cardone for remanufacture.

 

[youngstr]

You're absolutely right, I shuttered with horror when I saw brake fluid that I could not see thru. Thats when the sum of things that are wrong with my pm system dawned on me and I started looking at my replacement options. I had one other car in my entire life that had fluid that looked almost that bad, and that was my 69 impala, I bought it knowing I was gonna fix a lot of stuff. Same with my regal, I didn't pay that much for it, so I expected some big ticket stuff to be wrong with it. When I got it the electronics where half way converted and the vacuum lines...well they half of them were just hanging there not hooked up, turbo was turned down to 6 lbs of boost, yoke exiting the tranny was bent, it was lowered using the "Hood" method.....you know, just chop off the stock springs.... yeah, I spent 3 months giving it TLC and fixing stuff. So this is just another expected replacement....I'm sure I'll have more to come. Although I do look forward to the upgrades that become possible with some repairs. I've learned a bit about turbocharged motors, still lots to learn, I'm glad this forum is here and think the people that are in it are outstanding, thanks for all the help so far.

 

[dz28]

Yeesh! Another half day spent in the garage under the hood of the Buick with no luck Went completely through the step by step graciously provided by Zeus. Bleed down the ACC multiple times until fluid was coming back into the RES nice and clear. First couple of time there was so many micro bubbles I thought the fluid was milky. Once clear I went to the PM, pulled the two lines and installed the temp fittings and lines back into the RES. Went through at least a dozen pedal down cycles until zero air was coming out of the lines. Went to the four corners and both power bled and manually bled each corner. Pedal seemed to be responding until I powered up the first time. I'm back to a hard pedal (although not as bad as when I started), brake light, and no brakes (they are better than when started but will not stop the vehicle as designed). So needless to say I'm a bit frustrated and resigned to the fact I will have to turn the car over to someone who apparently knows what they are doing. Thanks for all the help and multiple replies; I really would like to get the car on the road, it can't rain every day the rest of the summer (like June has been here in Mich) and I'd really like to add to the 13 miles I've managed so far in 2008...

 

[zeus87gn]

dz,

Sorry you are having so much trouble.
I seem to be striking out these days.
I'm beginning to wonder if I missed somethig in my procedure.

The power bleeding may have churned up some air if you did it first.
Hard to say.

Let me know if I can be of any more help.

Z

 

[dz28]

Not really sure either, I did notice that the length of the hose going from the outlets on the side of the PM did make a difference. I shortened up the front hose as it seemed to keep sucking an air bubble back in on the pedal release. I must have bled the PM about 15 times before I was happy to move on to the 4 corners. Such is life; I spent a ton of money and a $hitpot full of years restoring a 68 Z/28 only to have brake problems all along the way. I had an NOS master cylinder that ended up needing a rebuild, that was problem number one, then had leakage at the front calipers due to stainless steel lines. I ended up replacing the calipers and redoing the short brake lines going from piston to piston on the caliper... what fun... did get the Camaro resolved but just can't seem to get this Buick done. I don't like the idea of converting over to vacuum brakes but am beginning to understand why many folks do. NOS PM sold over the weekend on eBay for $750 bucks... pretty pricey... I will report again once I resolve the ole girls problem...

 

[dz28]

Well, I've either entirely lost my luck with cars or am just having a bad year. I yanked the dreaded Powermaster and have installed the Hydroboost (I've started a separate thread on this nastiness!). I'm now at 7 days invested over the last 2.5 weeks. I now have the system completely in and have zero leaks in the two high pressure power steering lines. I have purged the system, bled out the brakes with a vacuum system and still have a major problem; the brakes are not releasing when the pedal is released. The brakes actually work, the pedal pressure feels like $hit however this must be associated with the brake release problem. I'm now wishing I had simply purchased a rebuilt PM and shoved it on the car; at least I'd be driving it by now...

 

[dz28]

After a few trying moments and lack of parts the vacuum brake system is on the car and surprise seems to be working. I have brakes, I have a good pedal, and other than a mysterious fluid lead I'm drivable. Not sure why I'm getting a bit of a fluid leak but will go underhood again tomorrow.

One word to the wise relative to PBS, Bob has had my hydroboost back since August 4th and still no refund even though both he, Roberto, and Jackson agreed to a refund, provided an RMA and a return shipment label for UPS. My only advice relative to PBS is to proceed with caution; many others have had great luck with Bob and god bless them. My luck was terrible as was my experience... I now have brakes on the Buick for the first time this summer and once I get my refund from PBS my life will be back in order.

For the many that offered words of advice, wisdom and everything else in between, thanks kindly. I'm once again a running member of the Turbo Buick community...

 

[excobraguy]

Just convert to vacuum already!!!!!!!!!

 

[dz28]

Maybe I wasn't clear; I now have GBodyparts.com vacuum brake system with Caspers billet vacuum block. Brakes work... have only driven up and down my street but is looking favorable to hit Woodward tonight!

 

[excobraguy]

Maybe I wasn't clear; I now have GBodyparts.com vacuum brake system with Caspers billet vacuum block. Brakes work... have only driven up and down my street but is looking favorable to hit Woodward tonight!

Good deal! Getting my junkyard pedal Thursday, hope to have mine fully converted by then. Powermasters are a joke..........glad you got yours going!

 

["Turbo-T"]

Zeus I think I'm beginning to understand the PM and how it works.....seems all it is, is a self contained unit that uses pressurized brake fluid to give you power brakes like a hydroboost....now how it actually makes the power I'm not sure of. But I see how your schematic shows of how the switch regulates when the pump motor comes on, and such.

Oh yeah...if your powermaster still works list it on ebay. I've seen them fetch more than what Kirbans would give you.