PS pump and gearbox extremely hot

[funknut]

1968 Charger, Borgeson PS gearbox, hydroboost w/ Wilwood MC and a recently rebuilt (under 250 miles) Federal pump.

Everything works fine when warming up/cold, but once up to temp I'm getting some very bizarre behavior. When cold, lots of power assist to the brakes, but when warm the power assist fades UNTIL I give it a bit of steering input, not much, less than 1/8 turn of the wheel. Then my power brakes come back for a short bit, usually long enough to stop the car, then rinse and repeat.

Car was running a bit hot, but I chalked that up to new radiator and elec. fans not quite dialed in. Once I got the car home I could smell something hot, so I dripped some water on various components to try and isolate. When I got to the PS pump it was sizzling hot, same with the PS gearbox. Fluid level looked ok.

Just a guess, but is the fluid boiling in the lines which causes the brakes to lose power assist?

What would cause such high heat? Bypass valve stuck?

I've read the Federal pumps aren't the best for hydroboost applications, so maybe it's time for a Saginaw/Borgeson unit? I have no problems upgrading if needed, but I just want to understand if I have other problems to sort out first.

Also, may be unrelated but every once in a while the brake pedal will not return all the way up, I have to pull it up with my foot.

Thanks in advance.

 

[65wgn440]

Sounds like a bad pump to me. Funny you would not have any related noise issues, though. Another thought, internal hose blockage (partial) issue ???

 

[funknut]

Yea it's definitely strange. No noise, no obvious bubbles that I can see. Good suggestion to check for blockage, I'll take it apart and see what I find.

 

[BergmanAutoCraft]

Your first issue is one with the box. Borgeson carries a 3 year warranty. I’m not sure if I sold it to you or not.
Your second issue with the hydroboost is partially from overheating fluid. Partially from the tee in the return possibly being too far away from the pump. Kind of the same scenario as the unit is sensing a restriction.
Bergmanautocraft.com

 

[funknut]

Thanks for the troubleshooting help.

A little bit of background.

Original setup:
- Hydroboost from Tallon Hydraulics
- Wilwood MC
- Federal PS pump
- Firm-feel rebuilt PS box

The original setup on the car worked well. Good power assist with the steering and brakes, but some vagueness in the steering, I was wondering if I could improve things with a Borgeson box.

I took the car apart in the spring of 2019 and am just now getting it back on the road, so basically 0 miles since then.

Setup from when I originally posted:
- Hydroboost from Tallon
- Wilwood MC
- Federal PS pump
- Borgeson steering box.

Yesterday I replaced the Federal pump with a Saginaw unit and replaced all the return lines to put the tee closer to the PS pump. There's only about 4" of hose between the tee and the pump now. Flushed and replaced the fluid. Return circuit should be free of any restrictions.

Started it up and noticed it was idling a bit low and now the brakes are self-applying when I give it any steering input at all.

I did a bit of searching and have read where the spool valve in the hydro boost unit can stick/fail and cause these symptoms. I will see about bypassing the hydro boost unit. If I bypass the hydro boost unit and the steering box has issues, what symptoms could I expect to see?

Thanks.

 

[MoparGuy68]

Did you install a cooler with the Borgeson system? I have a cooler installed on mine.

 

[funknut]

I plan to install a cooler if needed but with the amount of driving I’ve done so far I really can’t explain why it got so hot so fast.

I removed the hydroboost last night and will take it for a drive later today and see if anything has changed.

 

[BeeFast]

I'm also wanting to do the hydro upgrade this winter. Any updates?

 

[F4R/T]

I really think a cooler will help but what rear axle ratio do have also? Chrysler added a cooler when the gears got deeper.

 

[funknut]

Hydroboost was definitely acting up, but even with it removed I was still seeing temps over 260 at the gearbox. I installed a small Derale cooler in front of the radiator and it runs around 140f now.

Derale 13200 Power Steering... https://www.amazon.com/dp/B0006HNM66?ref=ppx_pop_mob_ap_share

 

[BergmanAutoCraft]

Here’s something else to check:

Remove the pressure line from the box. Looking inside at the flare seat adapter inside the port.

I’ve seen misalignment between the center of the adapter and the port in the box casting. If the port is obstructed by the flare adapter, lightly port the inside of the flare adapter to smooth out the passage to the box.