KenRudd

PS failed while on track, first session of day.
PS pump belt is fine.
No fluid loss.

Rack is a rebuilt unit with maybe 200 miles on it, including the ~100 mile drive to track.

Pump is of indeterminate age.

Any quick checks/tests I can run trackside with limited toolset?

How about when I get home, where to start?

Sorry if this is covered on a thread that would pop up in search, I'm in the paddock on phone with sketchy connection.

Crumpler

Hey Ken, sorry to hear that. Hope you weren't at risk on the track when system failed.
I'm sure we will get more advice for you when other people jump on. I just replaced entire system in mine so I will try and help anyway I can.

More info if you have time: what symptoms do you see right now? Resistance, noise, etc.

Check reservoir for strawberry froth.
Check outer boots for fluid, they can hold alot before you see it on the ground.

There isn't much that will fail in pump, if it spins, except the gasket, which you would see.
Internal rack seal failure most common at load.

I would not open banjo yet on powered line to rack, but that can be a way to verify supply. System will clear air afterwards.

Stay safe, Dave.

ammonman

Pump pulley bolts still there/not sheared off?
Can you see fluid movement in the reservoir with the cap removed?
If both of those check out then internal rack seals are the most likely candidate.

Mike

Imo000

Send it back to the rebuilder.

KenRudd

No obvious noise.
Not seeing anything in boots
Pump pully is in place with Belt
No strawberry froth

Crumpler

I think, unfortunately, your probably done for the weekend. Sorry Ken.
You can check for supply to the rack, if you have the tools there.
But, I assume it's a failure in the rack.
It sounds like you have steering and suspension, but just a hell of an effort required for turning?
I have heard of people track driving on de-powered racks, but I wouldn't.

KenRudd

Yeah, it's "drivable" but very heavy. Not going back out on track like this.
No way to check supply with equipment I have here.

Crumpler

I think the competition got off easy this time Mr. Rudd.

KenRudd

Ha!

FredR

Ken,

John [Firemn131] recently had a similar sounding mysterious issue after a rack rebuild- he found a little piece of plastic in the reservoir that he reckoned was blocking the outflow [strange though it seemed]. After removal the problem disappeared.

Lost any plastic bags recently?

john gill

I didnt see what car it was , but pretty typical of these pumps to cavitate in the heat of battle at track days , they spin too fast and will destroy thenselves at consistenat high rpm with track use.

I have destroyed plenty of the same pumps here in Queensland .
My rebuilder loves me .
A solution is too spin them slower , however given the position of the pump , not an easy task .
Lucky they are easy too rebuild if you have spares .
I converted my race car to electric, the best system I have on the car and by far the cheapest .

KenRudd

Nothing would make me happier than to discover the issue is with reservoir. Cheapest/Easiest fix in whole system. First place I will look.

KenRudd

This was first session of the day in cool early AM and not yet being driven hard. No noises or leak from pump. Can't rule it out yet, but does not seem like pump issue at this time.

KenRudd

On drive home I discovered that if I turn the steering wheel ~90 degrees left or more, the power kicked in all the way to full left stop, but the moment you begin to turn right, power assist stops.

KenRudd

Talked to seller. Pulling rack off tonight to send back as soon as I can get it packed and over to UPS, plus the original core for this one. ( So two racks total, long story)
Pulling rack is not the very worst 928 job, but I am frustrated that that I am doing it again so soon and it cost me an entire track weekend.