19mystic96

Hey guys,

So after blowing 2 4.6l cobra motors I finally had enough sense to fit an Ls1 into my SN95 cobra.

I got a great deal from a friend on a forged HCI 347 that is now in the car and running thanks to a PSI stand alone harness and a built T56. One of my few small problems is my braking system. I've got a hydroboost setup on the car being fed by the factory GM ls1 power steering pump. My brakes feel super stuff and the car stops very poorly. I purchased the borgeson GM pump shim kit to reduce the pressure for the mustang rack..

What could It be?

Pressure too high?
Bad pump?
Bad hydroboost?

terryr

Is it the stock hydroboost?

Either way, sometimes it takes awhile to get the air bubbles out of it. Until then it is spongy and/or grabs.

lsxRanger94

How many shims did you use? Is the steering twitchy or does it feel heavy?

19mystic96

Yea, Its a stock Mustang hydroboost.

any tricks to getting the air out easier?

I think i used 3 or 4. I don't remember for sure since its been a little while. It came with 5 but i didn't use them all. should I have used them all?

Borgeson said in their instructions that the mustang rack be approx. 1000psi. but after some searching another forum it said the PSI rating is about 750.

could that help?

lsxRanger94

The lower the pressure the longer it takes to pump up the accumulator in the hydroboost, but you also need the correct amount of volume of fluid. I would also make sure the air is out of the system. Proper bleeding procedure will take about 30 minute to an hour depending on how foamy the fluid is. Most likely if the system worked before the swap, it is in the pump pressure or the pump itself. F250s are switching to a larger orifice for correct pedal feel. You might try search that also.

bleeding procedure:

http://www.agrperformance.com/AGR-In...structions.pdf

19mystic96

Thanks, I'll try that.

Yea the system worked before the swap. Just this is slowing me down at the moment

terryr

I read the factory uses vacuum while filling. Don't know for sure. But they put thousands of cars down the line. They must have a quick way to do it.