Hydroboost problems

[M1Gunner]

The accumulator is there to hold reserve pressure like a vacuum brake booster. It’s just holds p.s. fluid under pressure in case you have a pump failure or belt break. With the engine off you should still have enough power assist to stop the vehicle.

 

[Matahoe]

That's the whole problem. It acts like it has reserve and sometimes it doesn't. Usually only when performing tests. According to the service manual my hydroboost could either be good or bad depending on how you interpret the instructions.

I turned off the engine, pumped the brake pedal 4 times (per service manual) and it depleted (pedal got hard) on the 5th pump. This is normal.

But here is the real kicker. The service manual then says to start the engine again and idle (for an unspecified amount of time). Then to turn off the engine and retest reserve. It says I should be able to get 1 reserve application right away. But I don't. The pedal is still hard from the previous test. However I might have not let the engine idle enough because the damn service manual doesn't specify!! You guys see my problem?

 

[HiHoeSilver]

That's the whole problem. Sometimes it has reserve and sometimes it doesn't. According to the service manual (which is vague on a number of isses) my hydroboost could either be good or bad depending on how you interpret the instructions.

I would definitely concur that it is either good or bad.

 

[Rocket Man]

I would definitely concur that it is either good or bad.

Agreed 10-100%.

 

[Matahoe]

Just found another hydroboost test proceedure. After doing the first test it says to turn the wheel to one of the stops for 5 seconds while idling. Then turn off engine, depress brake pedal and see if there is any power assist.

If this works I am going to call it good.

 

[mattbta]

Agreed 10-100%.

That's better than 10-200% right?

 

[Matahoe]

Figured it out. I'll leave you guys to imagine my outcome pending removal of the belittling remarks by the admin. However funny you thought they may have been ...they added nothing to this rather important discussion.

 

[Matahoe]

I would definitely concur that it is either good or bad.

Nate/Mark. I ammended my post while you were replying. Please read it again and you will think differently.

 

[Rocket Man]

Nate/Mark. I ammended my post while you were replying. Please read it again and you will think differently.

I was just lightening things up since it got a bit heavy earlier. I don't have hydroboost so I couldn't offer any help. I've just never heard of anyone driving at 45 and purposely turning the engine off to test the brakes so I was following in order to see why you would do that. Doing it while stopped makes sense. Sorry for being a smart ass, humor isn't my strong point.

 

[swathdiver]

Sorry for being a smart ass, humor isn't my strong point.