This can't Be Normal

[noel]

The Other day I notice on my 88T Supra when im idleing. If i keep pumping the brakes the car kinda wants to die
plus my Vac. Gauge starts to drop the faster i press the brake it goes from 21 [which i heard is perfect at Idle] to 18 to 14 i stop at 10 and the idle is around 500-400rpm This can't be Normal Right?

 

[IJ.]

Leaky booster.

 

[northwestsupra]

agreed. bout the only thing i can think of that would cause a vac. leak when hitting breaks. test it see if it holds vac or not

 

[IJ.]

They're designed to exhaust xx amount as you cycle the pedal but do end up leaky, often you feel this as a hard pedal or as a dodgy idle when getting on/off the brakes.

Replaced mine last year for the same reason.

 

[TurboStreetCar]

Well if your pumping the brakes rapidly it could cause that effect as the manifold has to keep the reserve in the booster at low pressure.

Your basically creating a vacuum leak as you press the brakes.

 

[Sprmcy]

most likely the booster will need to be replaced. i had that problem until i replaced it

 

[noel]

i dunno if it makes a difference i can pump the brakes fast/semi fast is makes no difference. The Vac. Gauge drops. As far as i know i dont have a Vac. Leak it holds perfect at 19-21 Vac. [of course without pumping the brakes lol]

From the Feedback is sounds like my Brakes Booster is Gone :3d_frown:
Is it difficult to replace? also what Kind of Price am i looking at ?

Thanxz for the Quick and accurate Replys

 

[IJ.]

Push the pedal and hold it down and see what happens.

 

[ForcedTorque]

From the Feedback is sounds like my Brakes Booster is Gone :3d_frown:
Is it difficult to replace? also what Kind of Price am i looking at ?

They are not difficult to replace at all. It's been a while for me, so memory is fading. I can't remember if you have to remove the pedal or not before removing it. It should be only 4 nuts to remove from the inside of the firewall to remove it. Of course, you will need to at least take the lines loose from the master cylinder. It's easier to go ahead and take the master off all together though.

As for price, I have no idea what a new one runs. I've got 2-3 used ones in my shed, but I have no idea of their condition.

 

[noel]

Push the pedal and hold it down and see what happens.

ALright this morning i held the brake pedal i lost alil vac. about 17-16 and slowly went back up to 21

 

[noel]

They are not difficult to replace at all. It's been a while for me, so memory is fading. I can't remember if you have to remove the pedal or not before removing it. It should be only 4 nuts to remove from the inside of the firewall to remove it. Of course, you will need to at least take the lines loose from the master cylinder. It's easier to go ahead and take the master off all together though.

As for price, I have no idea what a new one runs. I've got 2-3 used ones in my shed, but I have no idea of their condition.

im all about [do-it-yourself] ill try the install on my own Now i just need somewhere to buy the booster from it won't be EBAY lol