ISOTORQUE DIFF

Hey guys, My V8 has a mushy and deep pedal feel. I hit the brakes hard and it feels like I am pushing fluid and their is not much resistance. It then bits real hard at the end like it should and the brake warning light turns off. The light only comes on when its mushy. So there is a delay when I brake and I think its unsafe. Anyone know the problem?

bomb seals? It didn't look like it was leaking
brake booster?

Also where can I find a write up or diagram of the brake system? Am I right to say it works off of power steering pressure?

Thanks

Kneale Brownson

Brake pressure and power steering pressure are both developed by the same pump, but the pump has two sections, so in effect, they're separate. The front of the pump supplies the braking system. The rear supplies the steering.

Test the brake pressure accumulator (bomb): Drive car, park, shut off engine, pump brake pedal until it becomes hard. A new bomb should give 30 or more pumps. A fading bomb gives 10-15. A dead bomb gives zero.

If the bomb is OK, try disconnecting the return line from the brake booster to the hydraulics reservoir. If you get more than a few drips, it's leaking internally and not providing adequate boost.

Calbha

due to space in the engine bay like kneale was saying you have a hydroboost braking system. which can be different from the vaccum system. first of all what color is your fluid? where is the level at? where are your brake pads? did you check the master cylinder for leaks? did you check all the lines and hoses for leaks? all the fittings? did you try bleeding the system. mushy pedals usually first point to air in the system, (fluid cannot transmit pressure undimished with air inside it.) which is from boiling the brake fluid or it losing its boiling point from not being changed in so long. test your fluid too brake fluid is hygroscopic, it asorbs water from the air and retains it and this can cause old brake fluid to eat at the linings in your brake lines.

ISOTORQUE DIFF

So, the pedal gets hard at the first pump or so. It seems a new one is $300. Where is a good place to get one?

Also I think I need a new o2 sensor. The engine is not smooth and it has been more than 65,000 miles.

I have parts to make a diagnose light. would that tell me I need a o2 sensor? Where is a good place to get both the bomb and sensor?

Thanks

ISOTORQUE DIFF

I did bleed the system a few weeks ago. I put ATP Blue in and the level is good and at the time there was no leaking that we saw. I suspect the pads are low but they bit good. they squeal a bit when cold.

Kneale Brownson

There's a guy in Pennsylvania who used to recharge the hydraulic accumulators for about $75. Don't know if he's still at it. I've sent him an email to find out and will report back.

ISOTORQUE DIFF

Thanks

Calbha

What dot rating is ATP blue? btw you CANNOT use DOT5 with our cars it will ruin the abs system. you can however use DOT5.1 a little expensive and hard to come by but i always had good luck with it. Best bet is a high quality DOT4 brake fluid if you have any suspicion.

Calbha

also if you have 65k miles on the car and haven't done it yet.....you are going to seriously want to start considering doing a full timing belt service.

ISOTORQUE DIFF

I just did a timing belt service and changed all fluids. Thanks for the concern. I got all my fluids and parts from Blauparts.