Howdy, guys and gals.

2001 GV, automatic, 150k miles, pretty much stock.

Had transmission serviced Wed with total replacement pumped in.  Tech said it was difficuolt to get ALL the old fluid out.  Screens were very clean, and magnets had very little residue. 

Before this the brakes were working fine, as power assisted brakes should.  Could get the pedal to pump up at a stop, and also could get it up further with the adjusters in the rear.  After the tranny service, way different brake response.  More like manual than power.  Will still stop the trucklet, but 2-3 inches of pedal travel b4 engaging, and take spressure and way more than usual pedal travel to come to a stop.

SO, testing shows I have good vacuum at the booster.  Is the booster bad?  There is no bleed by in the master cylinder.  No connection to trans service that I can see, but never know.

Further, has anyone replaced a booster?  Part cost and where purchased?  Local numbers are just under 400 USD with minimum 4 day wait.  New and remanned.

I woud appreciate anything that may be relevant.  Including opinions on safety of vehicle with this problem.  Wife is supposed to take this GV to the beach this weekend.

Thanks,

Pat

Possible they crushed a brake line with their lift?

I'm seeing $188 boosters...
http://www.rockauto.com/catalog/x,carcode,1375129,parttype,1884

BUT! You can check yours by attaching one of those "Mini-Vac" hand pumps up to it to see if it holds vac.

I'd suspect that they (trans guys) didn't connect up a vac hose or like mentioned damaged a line or

I'd take that puppy back to the tranny guys.

One thing though...

Could get the pedal to pump up at a stop, and also could get it up further with the adjusters in the rear.  After the tranny service, way different brake response.

so you had THIS prob before the trans work? Your post has me confused. 

There, I fixed my spelling in the subject line.

Panic abated as I came up with alternative for wife, and her mom and sister just picked her up.  They are gonna stay locally, but away from me (yeah).  So I can get a good look in the am.

No problem b4 the trans service.

Lift was under tires, so no brake line crush expected.  My brake and front end guy whom I have known and trusted for 12+ years says different vacuum systems.  He says booster.  Says coincidence.

I did test by standard method of engine off, pump up pedal to release residual vacuum, start with pedal depressed and see what pedal does.  In this case, it sank nuch beyong where it began,
not a sign of booster failure according to what I have read.  OTOH< i do not have master cylinder blowby, but pedal does seem to hold quite low. 

There is a one-way check valve in the vacuum line that, IIRC, comes straight off the intake manifold to the booster.  I will inspect and test that tomorrow, as well as look closely at the trans and lines and such, with close attention to vacuum lines and such.  Maybe check the vac pressure off the intake. 

My biggest fear is that the pumping out of old fluid damaged some tranny internal part involved with vacuum.  I still have air lockers and such.

Non-linear post.  I apologize.  Report to follow after tomorrow's inspection.

Pat

So  did you get this problem solved on your truck?  What was the "final solution"?

Here is what I learned.

Close visual inspection revealed nothing remarkable, except as below.

Test for bad booster negative.

There is one-way check valve in vacuum line. Took off intake end and
no surprises. Removed booster end and there was rush of air. I
presume atmospheric pressure into booster chamber. Blew into intake
end and no flow, which is good. Booster end got no flow with low
lung pressure, and then increased pressure produced a click in the
valve, and then full flow. I suspect I was getting partial vacuum to
the booster. All is just fine now.

Why is it always the simple and cheap things?

During inspection, found single vertical cracks in the outboard boots
on the front drive. Other boots (inboard front drive and stteering
linkage) are fine. Very little lubricant around crack. Any concerns
regarding lockers (air) or wheel bearings?

Thanks,

Pat

I like those simple and cheap things!