Hydroboost problem?

psmvchaser

psmvchaser

Member
I installed a hydroboost and I'm trying to get used to the feel of it.

The pedal is very hard and almost feels like manual brakes. I do feel the slight pulsing or push back. I am worried there is a problem though and I want to know what I should check. It seems that I have to push the pedal too firmly for the response I am getting and it does not hold well if I try to build boost. It also feels like it is not releasing fully when I release the pedal.

I did mod the length of the rod, but I am thinking that may be the problem? Is there anything else I should look at?
 
psmvchaser

psmvchaser

Member
Re: Hydroboost problem?

I did bleed the system although my buddy seems to think it must have air in it. I just turned the wheel back and forth all the way numerous times for the ps system and then did a standard bleed from my speedbleeders. Maybe I'll bleed it again?

I used the astro master cylinder with my Ty reservoir.

I was just driving it and I was coming to a red light and lost my brakes for about a half second. They came back and the brake light went on. I'm not driving it again until I figure this out.
 
Maxtor

Maxtor

New member
Re: Hydroboost problem?

I bought my Hydroboost setup complete for our application and had it in place for about 4 years. The pedal is VERY hard. I bled the brakes a couple of times myself, then took it to a mechanic friend who has a power bleeder. Same results. When I put more pressure on the pedal, it gives me all the brake I want but definitely not the same as "normal" power brakes. It can hold any boost at the line. Since I drive my truck only on nice weekends I always have to recalibrate myself on the firmness of the pedal or I may sail through an intersection.

I have been tempted more than once to put my old vacuum assist master cylinder back on even though it wouldn't hold the truck at the line.
 
psmvchaser

psmvchaser

Member
Re: Hydroboost problem?

The sole reason I did it was to be able to hold boost at the line and it won't even do that right now. There has to be something wrong.
 
P

Poconojoe

Donating Member
Re: Hydroboost problem?

From my experiance with the hydroboost on the 1st gwen S10's its the nature of the beast, when using the astro van Hydroboost. I've been told if you want a softer petal, get one from a cadilac. I went to the yard to get one, but you need to almost remove the dash to get it out. I also have Hydroboost on my Safari hightop conversion van and there is night and day differance between that and the 1st gen S10. My 2nd gen S10 with hydroboost isn't as easy of a pedal as my Safari, but its a big inprovement over the 1st gen. I don't think the 1st gen has as good of a pedal ratio
 
Try Me

Try Me

New member
Re: Hydroboost problem?

Sounds like its not working at all. You should be able to hold any amount of boost at the line with it. Are the power steering lines hooked up correctly? My pedal isnt super hard, its actually very sensitive and usually after driving a normal vacuum booster car for a while i end up trying to throw myself through the windshield when I hit the brakes in the Sy. Are you sure its a good unit?
 
psmvchaser

psmvchaser

Member
Re: Hydroboost problem?

I'm going to go through and recheck everything make sure the lines are hooked up correctly etc.

I bought it from a member on the board, so I don't know if it is a good unit for sure because I don't know how to tell.
 
fivetodrive

fivetodrive

CRISPY
Re: Hydroboost problem?

Did you buy the hydrobooster from me? I cant remember all the parts I have sold. But if the unit is bad I will replace it with another unit. Let me know!

Aaron
 
psmvchaser

psmvchaser

Member
Re: Hydroboost problem?

fivetodrive said:
Did you buy the hydrobooster from me? I cant remember all the parts I have sold. But if the unit is bad I will replace it with another unit. Let me know!

Aaron
Click to expand...

Yes, I did. I'm not going to give up on it that quick though. I want to check everything first. Is there any way to tell if the unit itself is not working properly?
 
NecroWolf

NecroWolf

lost marbles member
Re: Hydroboost problem?

when you bleed a hydro boost setup you have to pump your brakes and crank the steering wheel. i work on hydroboost setups a lot and have seen them not bleed out with out doing this.
 
jwaller

jwaller

Evil Genius/SyTy Guru
Re: Hydroboost problem?

I bet you have the lines on the unit backwards. try swapping the inlet and outlet.
 
5

540Malibu

New member
Re: Hydroboost problem?

I have an astro unit in my big block s10...

you need to get all the air out of the system first... it took 2 hours of me turning the wheel back and forth with the engine off to get enough air out to feel any kind of assist... then i would start it up and it would work once or twice and then stiff... let it cool then cut the wheel back forth some more, bleeding the air out of the hydroboost unit is a pain and takes a while, but it sounds like that is your problem.
 
psmvchaser

psmvchaser

Member
Re: Hydroboost problem?

OK, so I went through everything and found that my right rear brake cylinder was broken. So while I was at it, I replaced all the hardware and rebuilt the rears. Don't ask how but while doing this I stabbed myself in the eye with a screwdriver and had a detour to the E.R. to get stitches. Luckily they think its just tissue and no serious damage.
So when I got home, to my wifes dismay, back out to the Ty. I get everything back together, and proceed to jack up the front and turn the wheel back and forth while pumping the brakes to bleed it.
When attempting to bleed as described above, there is suction noise that comes from the power steering cap and it forced power steering fluid to leak out with the cap on.
So I double check the fluids and decide to test it a little. Well, I get to 1800 RPMs and it pushes right through the brakes!
I've about HAD IT!
I need to get this working so I can go to Nats and run. I'm not going to only be able to do a vacuum launch and get my A$$ kicked.
Any more suggestions? Or if anyone lives fairly close to me with a knowledge of hydroboosts maybe I can stop by to get a helping hand?
 
TYTILIDIE

TYTILIDIE

METH HEAD
Re: Hydroboost problem?

Did you cut and paste your shaft? If so and you end up needing to buy a new unit, don't cut, I sell an adapter bracket that puts the shaft in place.
 
Try Me

Try Me

New member
Re: Hydroboost problem?

TYTILIDIE said:
Did you cut and paste your shaft? If so and you end up needing to buy a new unit, don't cut, I sell an adapter bracket that puts the shaft in place.
Click to expand...

I cut and rewelded mine quite a few miles ago and have never had a problem. Im curious to see what you find out but i agree if its forcing fluid out of the cap maybe the lines are backwards or not hooked up right. Maybe another possibility is one of the return lines is blocked/pinched?
 
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