trick to stop power steering/hydroboost fluid foaming

Discussion in 'The whoa and the sway.' started by sailbrd, Aug 28, 2013.

  1. sailbrd

    sailbrd Well-Known Member

    I have a custom power steering/hydoboost system. Uses a GM type 2 pump and a remote reservoir. The hydroboost kept foaming the the fluid and the pump would start to whine. Bleed the thing for hours and still could not stop the foaming. Old timer told me to put in some Dexron. Figured I had nothing to lose so put in about a third of a cup and foaming stopped! No more pump whine and everything feels better.
  2. bhambulldog

    bhambulldog 1955 76-RoadmasterRiviera

    I was thinking about putting one on my car.

    What would you tell me about Hydroboost? Good ? and Bad?
  3. ceas350

    ceas350 "THE BURNER"

    Wise man once told me power steering and Trans fluid are the same.
  4. sailbrd

    sailbrd Well-Known Member

    James, last week I would have told you to stay away from the hydroboost. Was going crazy trying to keep it from foaming. Now I am happy with it again. If you want to know what the system feels like drive a Chevy truck with a Duramax in it. I understand you are trying to get a dual master cylinder setup. Been thinking about doing that with my sisters 65 Mustang. On the Mustang we are thinking of a no power system. This would be much simpler and drum brakes do not need power due to servo effect. If you like the challenge of putting a complex system together and spending lots of money you will eventually like what you did.

    ---------- Post added at 12:21 PM ---------- Previous post was at 12:12 PM ----------

    Ceaser, wise man was wrong, tranny fluid is red :Smarty: There must be more anti foaming additives in the trans fluid or it would not have such a dramatic effect on my system. I was told that power steering fluid has a higher viscosity and some lubricants in it. So if you run pure tranny fluid you will burn your pump up. In my case the pump has to be better off without the air in the fluid.
  5. ceas350

    ceas350 "THE BURNER"

    Been using dexlll for years no prob x at all. It has stopped leaks quite a few times on diff vehicles.
  6. ks_skyhawk

    ks_skyhawk KS_Skyhawk

    I saw a You Tube video where a guy used a hand held vacuum pump to "suck" the bubbles out. I did this by bleeding it first with engine off. Then fired it up while making sure the reservoir remained above the fluid pickup. (The latter was while the engine was running. ) Turn the wheel slowly from side to side until the noise subsides and the bubbles are gone. 5-7 inches of vacuum during this process worked for me. The rig used a rubber valve cover oil fill plug ( off a Chevy V8 )drilled and tapped with a hose barb fitting in the center for the vacuum hose. Anything that you come up with to plug the top of the fluid tank will work.
  7. sailbrd

    sailbrd Well-Known Member

    I think I was getting some pump cavitation. Trans fluid has much better anti foaming additive because it helped a lot. Other things I learned if you are running remote reservoir are that your inlets should be at the bottom of the reservoir. I also have a hydroboost which compliments everything. Saw that same video, harder to do on mine because the cap is a lot like a valve cover oil fill hole. Other things the experts have told me is fluid is very important. They want you to use GM factory power steering fluid (which is red.... like... trans fluid!)
  8. ceas350

    ceas350 "THE BURNER"

  9. 70 gsconvt

    70 gsconvt Silver Level contributor

    Any determination as to what was causing it to foam in the first place? Was the pump speed too high? Would a different sized pulley have prevented the foaming?
  10. mr62buick

    mr62buick Well-Known Member

    To remove bubbles from fords, I use a hand vacuum pump... to remove cavitation bubbles, the AFT or Hydraulic fluid is too thin... I put in a little something extra for anti foaming
  11. sailbrd

    sailbrd Well-Known Member

    Don't think pump speed is a problem. The pulley ratio is close to 1:1, that is the standard ratio.

    Since I improved it so much with a little power steering fluid I think the main thing is just getting the details. The other part of the problem is the reservoir. The one I have does not have baffles and according to the experts the inlet is too high on the reservoir. So the next step is to get a Lee reservoir and some GM power steering fluid. Howe in CA also uses a -10 AN return line. Don't think I need that, there stuff is designed for off road racing.
  12. sailbrd

    sailbrd Well-Known Member

    I should update this. The solution is that you MUST have a properly designed reservoir. In my case with a remote reservoir make sure that the return from the gearbox goes in the bottom half of the reservoir. Then there should be a baffle above that. The return from the hydroboost should come in above the baffle. I had a custom reservoir made by Lee in CA. Now Turn One has good reservoirs.

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