Newbie w. New GN

[bryes]

Thanks Earl and Steve,


 I did hand lap the filter adapter before, but as it turns out that wasn't where the high spot was and I believe  that the outlet hole has always sealed. The high spot I was referring to was on the timing cover itself, right in the middle of where the leak was (where the arrow is in the picture a few posts back). I never touched the cover itself for fear of ruining the clearance.  I found the "defect" with  layout dye and it felt like maybe a 1/32" diameter raised spot,  I would have thought that it was some leftover gasket, but I had blasted that cover and the color was uniformly aluminum looking. With 400 grit paper I was able to gingerly polish it down with my finger.

Either way, I'll keep an eye on the oil pressure so if I do have a further issue I'll know where to look.

[earlbrown]

that area with the arrow is the highest pressure point on the engine.  That rectangle block is where the pressure is exiting the pump before it hit's any relief valving.   I know first hand how impossible it is to measure high and low spots by feel but anythigng near 1/32" might as well be a mile.   When you're dealing with a gasket that's only 6~8 thou thick, you just can't fill in stuff like that.

I hate to say it but pulling that cover and either spending lots of time flattening and hand lapping gears might be in your near future. (or getting a different cover and starting over).  Do you have lots of time porting and setting up that cover or is there no emotional attachment?

[bryes]

Thanks Earl

The picture below is a better description of what I sanded, don't pay too much attention to the scale, and I'm really not sure of the size or shape of whatever it was. I just know it was in that approximate position and that you could feel it and it was close to the edge. Maybe the best description is a burr,   and I  chamfered the edge until I didn't feel it anymore. I stole this picture from another site so hopefully whoever owns the copyright doesn't see this!


 I'm guessing labeled it 1/32" wide but it was probably smaller,   it was so small that I couldn't see it protruding, just feel it. I'm sure it wasn't pushed out that far, maybe more like ten or twenty thou?? It was sharp and sanded fast. I doubt in a way it was really the issue but it was the only thing I could find.


So you think it'll eventually leak? I'm not attached to it by any means, if it would I'd sure be open to replacing it.

[earlbrown]

I'm laying 2 feet from where that picture was taken.

On that section knock it down below flush. It's probably a booger sticking up where it got banged at some time. It's pretty common for the outside of the machined surface to have high spots from impact. (also high spots on the threaded holes from the tap pulling up a burr too)

Just make sure everything is nice and flat around the gear pocket, the rectangle hole, and he hole my drill is stuck in.  If you have a countersink set, put a healthy bevel on the 6 holes the bolts go through.  That'll spread the clamping load out and might help you make the difference between leaking and not leaking.

[bryes]

Thanks earl, that spot could have been a mark from me prying on it too. I remember it took me awhile to figure out the "hidden" screws behind the oil filter adapter   [size=78%]At any rate, if it starts leaking again or my oil pressure is not what it seems to be now, I'll have some more good information to go with the net time I remove that cover.[/size]


In the mean time, I worked on my Powermaster yesterday and found the fuse was blown. I replaced it to see what would happen, but still no motor sounds or change in pedal whatsoever. The pump motor (and fuse) itself was warm to the touch after leaving the ignition on for a few minutes, so I think that is likely the problem.


I have another working PM assembly (in theory), so my options are to either swap the motor out or the whole PM assembly. I'm leaning towards replacing the whole unit as I can clean it and wind up with fresh brake fluid. Any thoughts?

[daveismissing]

sounds like the motor is stuck, I'd swap it out but tap it with wrench for fun, probably starts up

[bryes]

Thanks,


I just went out there and beat on it some but it still didn't do anything. I could make it click by removing and re-installing the pressure switch connection, but that was it.


 I have to admit that I have a tender spot in my heart for cars that require some sort of "pre-starting" ritual, and that's ok for things like the starter or the radio or whatever. Heck, I tried to convince my wife how nice it was to have a good security system for our excursion, as I showed her how to jump the relay under the hood with a big crescent wrench.  But even I am not convinced that having a power brake system that requires a few firm whacks before it starts working properly is a good idea   So I think I'll switch it out when I get back like you suggested.

[daveismissing]

I had one that whenever I popped the hood to troubleshoot it would unstick and run.

[bryes]

I was able to swap out my Powermaster motor with another and the good news is that I now have pump noises under the hood and power brakes!     The bad news is that even after bleeding the accumulator, I I couldn't keep the  brake light from coming on.  


I swapped out the accumulator ball for another and then the brake light would turn off, but the motor would still turn on every single brake application. I assume this is not normal, I've read that the motor should come on every 3rd application of the brakes. I kept on bleeding the accumulator, but as I proceeded I noticed the accumulator reservoir level was continually decreasing at the same rate the rear DS reservoir was filling. There were also bubbles, similar to the accumulator reservoir in the ds rear, So it looks to me like fluid is escaping from one side to the other (See Below)....  the MC seal is leaking and  badly.  Time for a seal kit I suppose. I just can't catch a break with my PM, everything seems to have been bad, except for the pressure switch I guess!


I can see now why everyone converts these things to Vac or HB systems. Let me know if you think my diagnosis is correct.

[daveismissing]

This is a brand new accumulator?  How long does it stay pumped up without touching the brakes?

[SuperSix]

Yes - is this a know-good accumulator? Sounds to me like the ones you are using are weak.

[bryes]

thanks for the input,


It wasn't a new accumulator, I bought it off a board where it was advertised as a good used unit. I will say that swapping it in made a difference compared to my old unit for sure. Is there any way to check it to make sure?  That is really the only "known good" unit that I have available.


The reason that I think the MC is bad is because it seems to me that fluid seems to be transferring from the accumulator circuit (high pressure side I think) to the rear brake circuit. Which is why that chamber filled up (I originally had it probably 1/4 full) and why bubbles, similar to the PS chamber     I didn't think there was any way for this to happen unless the seal in the MC was bad. Is this bad reasoning?


Also I changed brake fluid and wiped out the reservoir until it was clean. The new fluid almost immediately turned the blacker color as can be seen in the picture. I was thinking this might also indicate bad rubber in the MC.

[SuperSix]

The only way I know of to test accumulators is a very expensive machine - it takes a lot of PSI to pressurize them.

Sounds like it's time to either replace the unit entirely, with a new accumulator (if still available) or change to hybroboost/vacuum.

[daveismissing]

The only things the accumulator does is stop the motor from cycling too often (overheat) and give you some stopping assistance if the motor dies.
FWIW- not recommended but I've gone a 1000 miles with the motor cycling once a minute.
An "unsafe" test would be -Unplug the motor and and hit the brakes from speed to see how much stop you get.

[bryes]

I've decided to put the powermaster on the back burner until I can get the car out for its first test drive (at least around the block), then I'll know where  i stand a little better. I will make sure the MC isn't blowing fluid through an internal seal before dumping more money into another accumulator.   I have a separate PM MC that I will try to get seals for in the mean time.


For the test drive, I think the only things I need to do are to round up some tires, and rig up the exhaust temporarily. Somehow the exhaust was snaped at the welds directly after the cat, so it needs to be re-welded. I don't have a mig welder down here but a guy I work with is supposedly getting one for christmas