Hydroboost issue- pedal not returning quickly
Thread Starter
Melting Slicks
Joined: Nov 2002
Posts: 2,231
Likes: 7
From: Fort Pierce Florida
Hydroboost issue- pedal not returning quickly
Need some help with the hydroboost. With the car off the pedal goes down an inch or so and then is really hard. When the car is on the pedal goes down a little further, but still gets really hard and then won't return quickly. I'm certain something is wrong, but not really sure where to start. I've never used hydroboost before so not really sure how the pedal should feel. The brakes are working, but the pedal just dosen't feel quite right.
I should also tell you this is a new system with all new lines, Wilwood MC, Wilwood calipers, proportioning valve, and silicone fluid. Outside of the silicone fluid I don't think the others would affect pedal feel though. I've pressure bled the system also, and I'm fairly confident I got all the air out.
Any ideas?
I should also tell you this is a new system with all new lines, Wilwood MC, Wilwood calipers, proportioning valve, and silicone fluid. Outside of the silicone fluid I don't think the others would affect pedal feel though. I've pressure bled the system also, and I'm fairly confident I got all the air out.
Any ideas?
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Mine felt funny for a while too, drive it around for a few hundred and forgeddabbodit 
Others have had the same problem as you, I think they said the brake was dragging or not releasing properly do a search, but the fix I believe is to let it settle in and work itself out
Others have had the same problem as you, I think they said the brake was dragging or not releasing properly do a search, but the fix I believe is to let it settle in and work itself out
Last edited by MotorHead; Dec 10, 2008 at 08:33 PM.
Le Mans Master
Joined: Apr 2001
Posts: 5,000
Likes: 1
From: Minneapolis, Mn USA
Air still in the system. Drive it longer and turn the wheels lock to lock a few more times to help dislodge air.
According to Norval, this may also happen to you all over again if you were to store it for several months -like winter. A few miles and its back to normal.
Brent.
According to Norval, this may also happen to you all over again if you were to store it for several months -like winter. A few miles and its back to normal.
Brent.
Le Mans Master
Joined: Feb 2000
Posts: 7,032
Likes: 2
From: Newburgh NY
Off the pedal is rock hard.
On the pedal is a little slow to return but once moving starting and stopping is fine. It will loosen up some. Make sure the resovoir is always topped off.
Backing out at a very slow speed where you have to touch the brakes takes some getting use to. When you let off the brake it takes a moment for the car to start moving again.
You'll Love it once you get use to it. Only thing that really took getting use to is sometimes going into a turn hard if you hammer the brakes you can sort of fell it in the steering wheel.
Thread Starter
Melting Slicks
Joined: Nov 2002
Posts: 2,231
Likes: 7
From: Fort Pierce Florida
Alright. I'd read that before in other HB threads, but had totally forgotten about it. I love things that require more driving to fix. Thanks for the help guys!
DB, return spring is still there.
DB, return spring is still there.
Race Director
Joined: Jul 2004
Posts: 12,696
Likes: 329
From: Scottsdale Arizona
Mine actually got worse with more driving and not better. The problem ended up being a flow restriction on the return fluid line. The actual fitting on the hydroboost unit had a very small ID. Drilled it out to about 1/4 inch ID and the problem went away.
Where did you get your hyrdroboost unit, from an eBay vendor in LA?
Where did you get your hyrdroboost unit, from an eBay vendor in LA?
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Melting Slicks
Joined: Jan 2006
Posts: 3,028
Likes: 2
From: North NJ
Like mentioned above, I've heard of your issue and some people say it goes away.
My had no issues from the very start. Got my unit from Hydroboost.com few years ago before they farmed out to distributors.
I've never seen someone go to your combo brake system too so that could be complicating things too.
First, make sure your hoses are correct so the flow is correct. Use the below diagrams.
Second, what power steering pump are you using? hopfully it flow is not restricted if your running power steering and hydro. I added a second return to help releive backpressure on the return lines. This could affect pedal return and feel. I've read on some S10 & muscle car forums that they've had issues with pedal return due to return line backpressure or installing the "T" junction improperly. I think someone used a simple "Y" junction instead of the "T" and that helped with flow.
Just ideas I am throwing out there.
But before you go pulling anything apart, put some miles on the car as long as the brakes do in fact stop the car when needed. See if it fixes itself with some use.
Good luck
My had no issues from the very start. Got my unit from Hydroboost.com few years ago before they farmed out to distributors.
I've never seen someone go to your combo brake system too so that could be complicating things too.
First, make sure your hoses are correct so the flow is correct. Use the below diagrams.
Second, what power steering pump are you using? hopfully it flow is not restricted if your running power steering and hydro. I added a second return to help releive backpressure on the return lines. This could affect pedal return and feel. I've read on some S10 & muscle car forums that they've had issues with pedal return due to return line backpressure or installing the "T" junction improperly. I think someone used a simple "Y" junction instead of the "T" and that helped with flow.
Just ideas I am throwing out there.
But before you go pulling anything apart, put some miles on the car as long as the brakes do in fact stop the car when needed. See if it fixes itself with some use.
Good luck
Race Director
Joined: Jul 2004
Posts: 12,696
Likes: 329
From: Scottsdale Arizona
Melting Slicks
Joined: Jan 2006
Posts: 3,028
Likes: 2
From: North NJ
I got an O-ring fitting from Hydratech, where I bought my hydroboost unit from. Then used a 90 deg aeroquip hose bend fitting to my stainless steel braided hose. Only issue I've had thus far is if you put a tight bend in a braided SS hose, over time with the torque movement and vibration from your engine the hose actually backed out of one of my fittings and leaked. So I ran a larger loop so there was no tension on the hose itself so the engine could torque back and forth and not tug on the hose. No leaks since.
Thread Starter
Melting Slicks
Joined: Nov 2002
Posts: 2,231
Likes: 7
From: Fort Pierce Florida
I just got the engine fired and had it moving up and down the driveway this week. Next week I'll take it on some backroads close to the house. have to be careful as I have no doors and no seatbelts! We'll see if the problem works itself out.
