Hydroboost issues

[rtreads]

Hydroboost issues
I have had my hydroboost installed for 3 years now. It has always worked great! ...until today.

So I tried to drive it today and the breaks are really soft and spongy. ...both with the motor off and running. When you press the brakes all the way with it running, it's much harder than normal to turn the steering wheel. There sre no leaks and the powersteering fluid is full. I am running the explorer serp front dress.

I have not driven it yet... I don't want to back out of the garage and into the neighbors hours!

So where do you think the problem lies? I think maybe a master cylinder??

Any help is appreciated!

See:
http://classicbroncos.com/forums/showth ... p?t=200589

[777mechanic]

ryan when i finally finished mine the power steering pump died , so to test it i put a direct reading guage on it and it would read only 500 psi and bump to 800 if you rev'd the engine . it should run to a 1000 once you rev it . when i turned it the pressure would drop and it took every thing i had to turn it. new pump problem solved .

[Justin]

x2. That sounds like a bad pump. A bad MC shouldn't affect your power steering, even if you were putting somewhat increased load on the braking system.

[sbolt19]

Yeah, bad pump. The brakes will feel like regular manual when the pump goes out, but you will still have them, but the steering is the big issue and indicator.

[rtreads]

Yeah, bad pump. The brakes will feel like regular manual when the pump goes out, but you will still have them, but the steering is the big issue and indicator.

What worries me is that the brakes are really soft when it's not running. ...when they are supposed to feel like non-power brakes.

I guess I will try the pump. Its not making noise or leaking, but I will try it.

[Justin]

Are they still soft after one pump? The hydroboost has a reservoir that allows the brakes to be powered for at least one solid stop if the engine is off, but I'm not sure how long that will stay pressurized for after the truck is turned off.

[sbolt19]

You will usually only get one solid pump with the engine off, like Justin said, but you will still feel a soft spongy pedal with the engine on. That's because the pump is still circulating fluid, just not at a high pressure. On mine, it feels like a really soft manual, but still similar. I had to rebuild my original pump once and thats what it did. I gotta get off my can and install the dual inlet pump that Zac gave me, which is a saganaw pump, and in my opinion is the route you should go if you haven't already done it.