Need some Serious Tech Advice regarding a Hydratech System and Issues I am having.

[CTSV]

I opted for this kit for my Mach1 pro Touring back in May since i almost wrecked my car with a low vacuum issue in a panic stopand at the time the shop that does all my work installed it correctly and the brakes worked fantastic. My power steering at the time was a Unisteer Power Rack and Pinion which used a GM Type 2 pump with plastic res.

Even though my brakes worked fine my steering got a bit stiff and there was a very mild groan coming from the Hydratech unit since it mounts to the firewall the resonance was audible in the interior. it was drivable at least.

Now i drove my car as such for a bit , maybe 250 miles total and i dropped it back off to the shop to have more work done. I then decided to upgrade my steering system and have everything done over because i was not happy with the Unisteer systems road feedback.

Here is what was installed.
Total Control Power Rack and Pinion
KRC Pro Aluminum Pump
PSC Hydroboost Reservoir
Aeroquip TFE braided lines
Hydratech brake assist unit remained mounted and wasn't touched except for them making a new return line off the brake assist using a -6AN line instead of the rubber hose.

The shop has been having a major struggle getting everything to work properly. They bled the car for the last 3 days on and off and noting is improving and there are no air bubbles in the fluid in the reservoir. The owner has spoken to Jim many times, called KRC and no matter what they try it just isn't working. KRC says the PSC reservoir seems to be one issue in its design based on the fact both returns are on the same plane as the-10 feed.

When the car is running the Hydratech unit groans like no tomorrow, the pump doesnt but the brake assist isn't working and the steering is hard as a rock. I cant drive it. this is after hours have been spent bleeding and there are no bubbles in the fluid


Here are some tech specs for you guys to digest.
My old steering system used a GM pump that flowed 2.5 gallons per minute
My old PS pump also had a 4.25 pulley
My old pulley ratio was .75:1 since my crank is 6 inches

The KRC Pro Pump flows 2.1 gallons per minute
The KRC pump has a specific pulley that is splined and it is 6 inches in diameter making my new ratio from the drive to driven 1:1

So guys what I want to know here is the following:

If my KRC pump is not pumping enough pressure would I be getting the symptoms mentioned above?
If my KRC Pump is pumping too much pressure would I be getting the symptoms mentioned above?

The shop does not know what to do anymore and they ordered a bunch of smaller and larger KRC flow valves for testing purposes.

Today the shop bypassed the pressure line on the system and basically took the pressure in and pressure out lines and used a male-female union. I stopped over when they did this and the car ran, steering works and there was NO NOISE with the Hydroboost bypassed on the pressure side. the return line was still hooked up.

They connected the Hydroboost pressure lines back and its growling like crazy, no brakes, no steering, no air bubbles.

Can anyone here can offer suggestions? I am paying out the nose for labor and im almost at the point of removing this Hydroboost and going Manual brakes. I have no real experience with this stuff but i am starting to think its a pressure issue or the Brake unit has a defective part inside.

Weeks keep passing and i am missing some awesome shows and cruise time and it sucks. I just want my car back.

[nicks67camaro]

I have a very similar set up. KCR pump (cast iron unit), Canton large capacity tank, Aeroquip lines, lee power steering box and hydroboost running c5 brakes. I had experienced a similar situation my car would run fine for about 10 minutes then all of a sudden the steering got hard and the power steering made an aweful groan. This was with the stock stock krc reservoir tank. I added the large capacity tank with baffles and added a power steering cooler which helped but it still made some groans. I ended up topping off the tank after running the car on jack stands and just working the steering wheel and it went away. I have track days, autocross's, and tons of street driving and no issue. I would see if your reservoir has baffles, and is totally topped off since it made all the difference in the world for me. also try taking the load off the wheels if you haven't yet and then work the steering and pump. Good luck!

[CTSV]

Nick thanks for the reply. They had the car on the lift when bleeding and i saw for myself there was not a single bubble and the fluid in the res did go up and down from lock to lock

now the PSC res i bought did have a filter inside of it and the shop removed it and the groan got better.

I just can not seem to think this is an air issue. I have no plans to add a cooler as I am already fed up with all the lines i have under the hood so far.

this is just a real crazy issue and it has me at my wits end. Il see what happens when they install high flow valves Saturday, I am hoping something at least improved.

Do you think any of the other info i posted is relevant toward this issue with the flow reduction and larger pulley being driven?

[nicks67camaro]

My pulley is set a little aggressive. At top RPM it is is at the top of the KRC operating range. I have the default rate flow valve in. What type of flow requirements does that TCP rack and pinion need?
Couple other dumb things to check...
- is the reservoir higher than the pump?
- are you totally sealed on -10an feed line?
- I would put the baffles back in and try topping off the fluid level while the car is running.

Keep at it....

[CTSV]

..
- is the reservoir higher than the pump?
- are you totally sealed on -10an feed line?
- I would put the baffles back in and try topping off the fluid level while the car is running.

Keep at it....[/QUOTE]

they tried all of this, the shop just called me they installed a 1.8 flow valve and a 2.3 and nothing changed they keep telling me something inside the hydraboost unit is causing a flow issue and the pressure is backing up into the pump like a stuck valve inside the brake assist unit. I have no idea but they will try some more stuff tomorrow then the last resort is the hydroboost comes out and will get sent back for inspection and testing, When the hydroboost gets bypassed the steering works perfectly and there is no noise. Does anyone know where these hydroboost units are derived from, like application etc? And are they internally serviceable?

[Fuelie Nova]

I run the Hydratech setup with the newest KRC pro series alum pump and the PSC reservoir and have no noise at all. I definitely run the filter and have a short direct down hill shot with the feed line to the pump. Maybe Paul will chime in here. The only difference I have is the Flaming River Billet rack and pinion unit. Before I took it out and sent it back I would definitely want to talk with Paul at Hydratech. Jim is good but Paul is GREAT.
Tom

[CTSV]

I run the Hydratech setup with the newest KRC pro series alum pump and the PSC reservoir and have no noise at all. I definitely run the filter and have a short direct down hill shot with the feed line to the pump. Maybe Paul will chime in here. The only difference I have is the Flaming River Billet rack and pinion unit. Before I took it out and sent it back I would definitely want to talk with Paul at Hydratech. Jim is good but Paul is GREAT.
Tom
Tom can you or anyone PM me Pauls contact info, I will pass it along to the shop on Monday and make them call as I am not technically versed to know what the heck is going on with my system.

[Hydratech®]

Hi guys - sorry I couldn't chime in this weekend!

The most notable tech detail about the hydraulic brake systems is found in this statement below:

When your foot is not on the brakes / brake unit not applied, it is literally a port to port interconnect on the brake unit. Spoken a different way, the hydroboost unit is an open center hydraulic device, which means that it is invisible to the PS system when the brake is not being applied = it may as well just be part of the high pressure hose between the PS pump and the steering gear. That being stated, make 100% sure that the brake pedal rod adjustment under the dash isn’t set too aggressively, as we have seen brake light switch and rubber pedal stop bumper adjustments at fault for not allowing the brake unit to go into a full state of release = back off the pedal rod adjustment if needed to make sure that there is zero preload on the brake unit input piston when the brakes are not in use or temporarily disconnect the brake pedal rod linkage entirely. You can also take a rubber tipped blow gun and blow back and forth through the high pressure ports on the brake unit – make sure to have a towel handy as some fluid will blow out. If you cannot blow through the high pressure ports on the brake unit, remove the master cylinder and then tap the master cylinder pushrod inward firmly using an average hammer, as this will force a sticking pressure control valve inside of the brake unit to free up (if some fleck of debris has possibly gotten into it and hung it up).

People picture all kinds of strange gizmos and widgets inside of these types of brake units, though the functions are actually very simple. There is a spool valve that controls pressure when you apply the brakes, essentially commanding up the PS pump pressures from the pump and allowing that pressure to rise in the main body of the brake unit (which applies force to the output / power piston providing amplification). I would also like to add that these types of brake units do not make any noise, save for an occasional just about inaudible squish sound when you hit the brakes before starting the engine (releases pressurized PS fluid stored up in the accumulator). Any other noise, such as whining concerns, are indeed PS pump noises (frequency telegraphing through the hydraulic PS system). When it is just a PS pump bolted to an engine, and a steering gear bolted to a frame, it makes noises harder to hear. When you have a PS driven component bolted to the firewall, PS system frequencies can intrude into the passenger compartment (an indicator that the PS pump is running noisy).

62698

The above exploded view may look complicated, though the spool valve itself is actuated by the pressure applied to the brake pedal (spool valve lever presses / plunges the spool valve inward as further pedal pressure is applied).

62703

62704

The area where I am indicating with the pen is the "open center" area of the valve. When the valve is sitting in its "neutral / brakes not applied position" within the casting, the two high pressure ports on the brake unit are in alignment with this area of the valve. This means that all fluid from the power steering pump enters into the port nearest the accumulator cylinder, flows around the area indicated by my pen in the above image, then out the port on the opposite side of the casting (out to the steering gear high pressure input). That is how and why this is referred to as an open center hydraulic valve, and why it is invisible to the power steering system when your foot is not on the brakes. In the open center mode / wide open, it is truly just as if there was a fitting in the PS high pressure output line between the PS pump high pressure output and steering gear high pressure input (as if the two high pressure lines at the brake assist unit were interconnected).

The most obvious thing to do is to make 100% certain that the lines are connected to the brake unit properly:

62705

Do please note that this is the BOTTOM view of most of the systems we produce (so it may look backwards at first glance depending upon how you may be looking at it).

What is even more interesting is that you will still have full flow through the brake unit high pressure ports to the steering even if you accidentally have the high pressure lines connected BACKWARDS (!). The braking won't work properly when connected backwards, but the steering remains fully operational as per the open center in the hydraulic valve.

Short of a major obstruction in the ports (rubber cap, small chunk of rag or whatever else you could imagine), there is nothing that can cause a problem of no flow to the steering, unless the spool valve has jammed into its fully plunged position. This can happen due a fleck of debris / metal particulate getting into the brake unit, as the spool valve operates on a half a thousandth of clearance in the casting. IF the spool valve was jammed in the "apply" position, the brakes would lock on the minute you fired up the engine (when the PS pump builds pressure). The brakes would release as soon as you killed the engine. Even under this circumstance, the steering would still work, as the pressure from the pump would still flow through the brake unit and function the steering. If you have a factory hydroboost equipped vehicle, jump in, apply the brakes firmly (because you may be parked on a steep hill), then fire up the engine, the steering would obviously still work (just brakes applied at a high level of driver input / brake amplification commanded).

The summary here is that IF you can blow air freely back and forth between the two high pressure ports, then the valve is in its open center (wide open) position. You can see that it is not any kind of obstruction to flow, and may as well truly be just a fitting installed in the PS lines (just as if you interconnected to the two high pressure lines as stated in the first post). If you cannot blow through these two high pressure ports freely, then you would need to send the brake unit back in to us so that we can bench test / inspect it.

The question of what these units are = currently using Bosch 2013 GM and Ford design heavy duty production units sourced from various OE applications. They *are* serviceable, but can be dangerous to work with if the accumulator pressures are not conclusively discharged before attempting disassembly. It is like an auto trans, or Rochester Q-jet carb - you better know what you're doing before you attempt to monkey with one of these!

I am always here, though exceptionally busy. When a tech call comes in, Jim does the job 100%, though may put you on hold to go back out to the shop to compare notes with me for accuracy. If there is a case here where your shop would like to speak to me directly, it can be done, though it still starts with Jim. If I am currently in the middle of a procedure that I cannot break away from, arrangements can be made for me to get into a call back.

Thank you for choosing Hydratech!

:cheers:

[CTSV]

Finally fixed, a plastic piece from the old type 2 GM pump broke off and entered the line causing a line blockage on the pressure side, everything came off, inspected and it was found. got it back last night. the piece that broke off the GM pump was part of the vent cap, it was plastic. total disaster finding this. OMG

[Fuelie Nova]

Glad to hear you found the problem!
Tom

[Hydratech®]

This is one of the strangest cases I have seen, as far as what was ultimately found to be the troublemaker. I am happy to have been of assistance, and am glad that the issues have been conclusively identified and resolved.

Thank you for choosing Hydratech!

:6gears:

[CTSV]

This is one of the strangest cases I have seen, as far as what was ultimately found to be the troublemaker. I am happy to have been of assistance, and am glad that the issues have been conclusively identified and resolved.

Thank you for choosing Hydratech!

:6gears:

Paul i have to see if the shop took a photo of what came out of the line, we got so mad we smashed the old GM pump and tossed it for the stress it gave everyone. the piece that was stuck was from the vented plastic cap.