98 lx470 booster/master squeeling noise

[happy the man]

I'm getting a squeel noise from the master cylinder area. I replaced the pump motor (used) and rebuilt the master two years ago but at that time I did not replace the accumulator. The pump motor sounds fine to me, and the squealing noise only occurs after the pump motor has run for several seconds.

Only guessing, but to me it sounds like the noise starts when the accumulator begins to pressurize. Error codes are c1256 and c1252.

Can anyone provide some feedback or thoughts about whether this sounds like just the accumulator? Would love to hear them. Thanks and happy New Year!

 

[DJWUZJ]

Mine has been running a bit louder and longer than I seem to remember... maybe just me. Usually about 15 seconds on start-up, and 3-5 seconds about a minute after that.

 

[happy the man]

Thanks DJW. I will put a clock on the length of time that mine runs before it stops tonight and post for comparison. Just a guess but I have a feeling that once the MC starts to go the pump and probably accumulator begin to work harder to compensate. Might be the reason why the dealers usually recommend replacing the entire unit??

 

[happy the man]

DJW - put a clock on my 2005 pump after pumping the brake pedal 20 times with key off to deplete any pressure in the system. Note that this is not the vehicle I'm having the issue with... my 2005 only has 100k miles on it right now. Approximate time was 17-18 seconds.

The pump noise seems about the same as my 1998, which is at the shop now so I can't time that one. The shop is telling me it is the pump motor again this morning, even though I told them I swapped this pump out two years ago. Although this 98 has high mileage, I've only put 10k on it max in the past two years, so not sure what to do. When the old pump died it did not sound as strong as the pump motor that is in it.

Anyone else have any thoughts?

 

[happy the man]

Asked the mechanic if they would put 12v to the pump motor directly. They finally got to it - I think - and don't seem to have any specific opinion other than swapping out the entire pump/master/abs/accumulator unit based on a recommendation they are getting from a lexus dealer.

Now I'm wondering whether to order the pump and accumulator or the whole unit from cruiserparts. Frustrating... been sitting there for a week now. Thinking I should have just done it myself again.

Anyone have thoughts on whether any other part of the system would have caused the pump and/or accumulator to fail? Or, maybe I just got bad parts last time. cruiserparts.net didn't have them when this happened the first time.

Codes are c1252 and 1256. According to the manual, looks like the only other thing it could be is the "Pressure Switch - PH PL". Not sure what/where that is. http://clients.btwelve.com/pics/lx470_brake-mstrcyl-diagnostics.pdf

 

[happy the man]

I just stopped by the shop to confirm no VSC on my '98 before buying any parts. Put the key in and no squealing noise, no buzzer and no abnormal lights. Now wondering what a dealer will give me for it...