1987 5000 TQ Brake Warning light

[Bernard Littau]

Hi Nick,

What you describe below is a classic case of having a bad hydraulic 
accumulator.  We call the hydraulic accumulator the "bomb" around this 
list, so search on bomb for other posts over the years.

The pulsing and the warning light are classic symptoms.  The bomb is 
less than $200 from what I recollect (been a while since mine went 
bad).  Replacement is not complicated, but you need to make sure you 
remove any residual hydraulic pressure from the system by pumping the 
brakes before you disconnect the hydraulic line.

A test for the bomb being bad is as follows:
1) run the car for a while (best to do this when you get home after a 
drive of some length)
2) park
3) shut off the car
4) depress the brake pedal, putting some good foot pressure on it
5) let up the brake pedal (4 and 5 together constitute a "pump" of the 
pedal)
6) repeat 4-5, counting depressions (pumps) of the pedal until the pedal 
gets hard.

The pedal gets hard when you loose the hydraulic assist.  In your case, 
it may go hard immediately, so that is zero or one pump.  A good bomb 
will go for 30 pumps with assist.  Contrast what the pedal feels like 
when you apply it with the engine running, and with the engine off.  
With the engine on the pedal should be "soft" to push.

Best,

Bernard Littau
Woodinville, WA
'88 5ktq

Nick wrote:

>I own a 1987 5000CSTQ. I have had problems lately with
>the warning light soming on when i brake. I have
>filled all the fluids to the max line. The problem is
>that when i push down on the pedal with a good amount
>of force, i feel a pulsing and the warning light will
>come on. What could be the cause and how difficult
>would it be to fix?
>
>Another problem with the same car i noticed today
>while listening under the hood. At approximately 2400
>rpm...and at exactly this point, there is a
>grinding/shaking noise the comes from (it sounds like)
>somehwere near the transmission. My car is a manual.
>What could cause such a sound at a specific rpm? 
>
>
>Thanks for the help.
>
>
>Nick 
>
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