LS1 and hydroboost
I know, old thread... new problem...
I'm using an F-body PS pump with my hydroboost and a quick ratio steering box...
Does this pump not have enough volume to run both?
The problem I'm having, since it's a new install, is that when I press the brake pedal down, I lose steering assist, and then it comes back when I let off the pedal.
What can I do to increase the volume, and/or pressure for this pump? I think this might be my issue... let me know if it is not...
I've also plumbed in a Heidts adjustable pressure valve for my steering, pre-hydroboost. I haven't reduced any pressure yet on this valve, but I am thinking maybe it needs to go after the HB and before the steering box so as to not reduce pressure to the booster and still change steering effort.
I wasn't sure if this change in pressure would significantly reduce hydroboost functionality.
I'm using an F-body PS pump with my hydroboost and a quick ratio steering box...
Does this pump not have enough volume to run both?
The problem I'm having, since it's a new install, is that when I press the brake pedal down, I lose steering assist, and then it comes back when I let off the pedal.
What can I do to increase the volume, and/or pressure for this pump? I think this might be my issue... let me know if it is not...
I've also plumbed in a Heidts adjustable pressure valve for my steering, pre-hydroboost. I haven't reduced any pressure yet on this valve, but I am thinking maybe it needs to go after the HB and before the steering box so as to not reduce pressure to the booster and still change steering effort.
I wasn't sure if this change in pressure would significantly reduce hydroboost functionality.
I would make sure you have all the air out of the system first, this can take some time, then if that doesn't work, take the heidts flow valve out. You only really need to reduce the flow volume on a rack and pinion, so with a box I would think the factory pump would be fine. If you do need to cut it down, you can change the flow control valve. Ive been running an F body pump and hydroboost with a mustang II rack for years and works fine.
I changed the routing of the valve to be between the HB and the steering box. That way, whatever reduction in pressure I do end up putting in is in the steering effort alone and not to the booster.
Anyone have a reliable source for how to bleed this whole system? I've seen a few different variations; some running the car, and some without.
If you think the box needs more pressure than the pump can supply, then why are you using a reducer at all? That said, GM has used the same pump for years and on many different applications, some of which are gear boxes and not racks. Early S-10 had a box with that same pump, only the flow control valve was different. Adding a hydroboost doesnt affect anything, it wont cut down the pressure to the box at all. I was actually hoping it would on mine , but made no change in steering effort. Most of these typeII pumps have about a 2-3 gpm flow control valve, I'm running a smaller one that I believe is a 1.5gpm valve and everything works good.
If you think the box needs more pressure than the pump can supply, then why are you using a reducer at all? That said, GM has used the same pump for years and on many different applications, some of which are gear boxes and not racks. Early S-10 had a box with that same pump, only the flow control valve was different. Adding a hydroboost doesnt affect anything, it wont cut down the pressure to the box at all. I was actually hoping it would on mine , but made no change in steering effort. Most of these typeII pumps have about a 2-3 gpm flow control valve, I'm running a smaller one that I believe is a 1.5gpm valve and everything works good.
I think I may just simply not have bled the system enough.
My main issue I think was that when the pedal was pressed I lost assist. So I'm hoping to understand/diagnose this symptom.
Last edited by ryanleiker; May 31, 2016 at 12:01 PM.
I've got my system back up and running.
Ls1 pump - hydroboost - pressure reducing valve(no reduction yet) - quick ratio box - reservoir - back to pump.
Right now this is my issue:
I can rev up the engine to about 2000rpm and have good brakes and good steering assist. When the brakes are pressed and I'm turning the wheel, the steering assist just drops off. As soon as the pedal is released, the steering assist comes back and I can basically pulse this same rhythm on command.
When I had the Saginaw pump, the system worked perfectly. Of course, it was a pump designed for hydroboost and the only thing that should affect this system that I've changed is the pump, to a Camero type II pump.
Is this a problem of not enough volume, where I could just drill out a fitting on the pump?
Or, is it possible that my hydroboost or pump is bad? Both are rebuilt units from the parts store.
Ls1 pump - hydroboost - pressure reducing valve(no reduction yet) - quick ratio box - reservoir - back to pump.
Right now this is my issue:
I can rev up the engine to about 2000rpm and have good brakes and good steering assist. When the brakes are pressed and I'm turning the wheel, the steering assist just drops off. As soon as the pedal is released, the steering assist comes back and I can basically pulse this same rhythm on command.
When I had the Saginaw pump, the system worked perfectly. Of course, it was a pump designed for hydroboost and the only thing that should affect this system that I've changed is the pump, to a Camero type II pump.
Is this a problem of not enough volume, where I could just drill out a fitting on the pump?
Or, is it possible that my hydroboost or pump is bad? Both are rebuilt units from the parts store.
TECH Resident
Joined: Mar 2012
Posts: 821
Likes: 4
From: Elkridge MD
Did you bleed the system after install? You need to get every bubble out of the system or you are going to feel some slop either in braking or steering. Even if bled perfectly, you may still notice a slight feeling in your steering wheel when you hit the brakes turning (like while parking). Eventually this will work itself out though, but it may take a few hundred miles of driving.
Also, if you are running the return line to a T-fitting, you want the T to be as close to the reservoir as you can get it.
I am running a stock LS2 (GTO) pump with no problems at all.
Also, if you are running the return line to a T-fitting, you want the T to be as close to the reservoir as you can get it.
I am running a stock LS2 (GTO) pump with no problems at all.
Did you bleed the system after install? You need to get every bubble out of the system or you are going to feel some slop either in braking or steering. Even if bled perfectly, you may still notice a slight feeling in your steering wheel when you hit the brakes turning (like while parking). Eventually this will work itself out though, but it may take a few hundred miles of driving.
Also, if you are running the return line to a T-fitting, you want the T to be as close to the reservoir as you can get it.
I am running a stock LS2 (GTO) pump with no problems at all.
Also, if you are running the return line to a T-fitting, you want the T to be as close to the reservoir as you can get it.
I am running a stock LS2 (GTO) pump with no problems at all.
I think I bled the system... I primed the system by cranking the engine, then bled the hydroboost by depleting the pressure in the accumulator. Then reprimed the system, Raised the wheels and turned them several times lock to lock and checked the fluid constantly.
I did take the car around the block yesterday and didn't really notice any issues, except when I tried to 3-point turn. The steering assist just stopped when I needed to control the brakes simultaneously. I'll see if it works itself out. Maybe I'll keep trying to bleed the steering box and keep driving it.
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I want to bring this back up...I am having the EXACT same issues and I have bled the hell outta my system, shimmed the hell outta the pressure valve, changed to a restrictive outlet fitting, drilled it out, et.
I still loose steering when I hit the brakes AND my steering is too touchy. When I drive and just touch the brakes, it almost locks up. No clue what to do...might just pull that hydroboost off and go manual brakes....need some help if possible...at my wits end
I still loose steering when I hit the brakes AND my steering is too touchy. When I drive and just touch the brakes, it almost locks up. No clue what to do...might just pull that hydroboost off and go manual brakes....need some help if possible...at my wits end
TECH Enthusiast
Joined: Dec 2006
Posts: 514
Likes: 0
From: Grafton MA
I was told to use a 1 1/8 if I was going to use hydroboost.
Have you tried taking all the restrictions out and seeing how it drives that way, then building or changing from that point? Or have you already started from there and worked your way to these drilled out fitting and restrictions?
Also how do you have it plumbed? Are you using a T fitting or another port on the reservoir?
Have you tried taking all the restrictions out and seeing how it drives that way, then building or changing from that point? Or have you already started from there and worked your way to these drilled out fitting and restrictions?
Also how do you have it plumbed? Are you using a T fitting or another port on the reservoir?
I may switch over to a 1" master cylinder in hopes that I get more pedal travel. Having so much assist in a short pedal is almost too touchy.
I'm running a 1977 Corvette Disc/Disc master
I'm running a 1977 Corvette Disc/Disc master
I had hydro boosts in my 66 stang and 67 Nova.
That was my only complaint it was a bit over assisted. With C5 brakes all around on both cars if you hit the brakes even somewhat hard it would put your nose up against the wind shield.
I did have to add a remote reservoir with a filter to get out the "micro bubbles". This was on advice from Paul at Hydro Tech.
That was my only complaint it was a bit over assisted. With C5 brakes all around on both cars if you hit the brakes even somewhat hard it would put your nose up against the wind shield.
I did have to add a remote reservoir with a filter to get out the "micro bubbles". This was on advice from Paul at Hydro Tech.
I had hydro boosts in my 66 stang and 67 Nova.
That was my only complaint it was a bit over assisted. With C5 brakes all around on both cars if you hit the brakes even somewhat hard it would put your nose up against the wind shield.
I did have to add a remote reservoir with a filter to get out the "micro bubbles". This was on advice from Paul at Hydro Tech.
That was my only complaint it was a bit over assisted. With C5 brakes all around on both cars if you hit the brakes even somewhat hard it would put your nose up against the wind shield.
I did have to add a remote reservoir with a filter to get out the "micro bubbles". This was on advice from Paul at Hydro Tech.
Also, would the cooler and filter be placed in the return line, pre-reservoir?
