Tuesday, September 06, 2005 - 10:23 pm, by: Roger Costello(Roger)
Hi,
This is a common problem on Lexus LS400's, it probably is on Soarer's and Celsior's as well. The basic system is the same on both the V8's and Six's. Does anyone else have PS fluid disappearing without a trace?
A few years back our 1991 LS400 started using a little and eventually a lot of PS fluid even after new hoses plus a full pump reseal. The cause was a leaky diaphragm inside the vacuum pressure switch that lifts idle speed when the PS load increases. This lets PS fluid from the high pressure side of the pump seep/dribble/piss into the inlet manifold via the vacuum hose. Symptoms were a puff of smoke at startup and PS fluid disappearing somewhere. Lexus said it was a very common problem along with the PS Pump needing rebuilding and owing to the cost of the part, not cheap to fix. From memory I think it was about $450.
My 1991 UZZ31 Soarer recently started using PS fluid with no apparent leaks and when I pull the relevant vacuum hose off the inlet manifold there is PS fluid dribbling out of it. For a 1991 UZZ31 p/n for the valve is 17630-70020, description is "valve assy, air control". The same part number valve is used on everything from Celica's to Crown's. It lives on the union connecting the outlet of the PS pump to the high pressure hose. There are different p/n's for later/other Soarers so check first if you are ordering a replacement.
Given the ridiculous price of the switch at almost $400 and its small size it could be worth sourcing them from Japan. I will probably have to go and get one from Toyota because it is a bit too urgent. The problem does start at just a few cc's per month and get's progressively worse over time. I can only find one unresolved reference to this in the ALSC archive and a few on US sites. Lexus of Perth tell me they have had this happen on many of the older LS400's in WA so this could be a problem we should all watch out for.
Regards
Roger
Neil Griffiths Trader NSW 1 x JZZ30,2 x UZZ31,1 x UZZ32,1 x UZZ Track Car,1 x AeroCabin,1 x Crown V8,1 x Celsior
Wednesday, September 07, 2005 - 07:26 am, by: Neil Griffiths(Aussiesc)
Roger,,Just disconect the 2 hoses..Block the Vacc 1 to the manifold..No problems doing this.. Just source a used 1 from the Wreckers at your own pace..
Wednesday, September 07, 2005 - 08:46 am, by: Don Bagnall(Baggs)
That MAY explain why some of the older Celsiors from Japan are a bit smokey on initial start up, like Peter Scott described when he was in the process of purchasing his Celsior.
Certainly something worth checking before condeming a possible Celsior/LS400/Soarer purchase.
Wednesday, September 07, 2005 - 03:19 pm, by: Roger Costello(Roger)
Neil,
Thanks, I did that on the LS400. The switch kept pissing out fluid and it's under a lot of pressure. When I blocked the two vacuum lines the fluid starts coming out between the plastic moulding and the metal body. Ended up leaving the vacuum lines connected because it was the cleaner of two evil's. I will keep trying wreckers but so far no joy.
Wednesday, September 07, 2005 - 04:45 pm, by: Roger Costello(Roger)
Neil,
Good work around if the part is unaffordable/unavailable, I should have thought of the tapered bung myself, Thanks!
For those contemplating this as a permanent fix the only downside is you can stall the engine at idle by loading up the power steering while parking etc. No big deal but that's what the idle lift is for.
Roger
Neil Griffiths Trader NSW 1 x JZZ30,2 x UZZ31,1 x UZZ32,1 x UZZ Track Car,1 x AeroCabin,1 x Crown V8,1 x Celsior
Wednesday, September 07, 2005 - 06:33 pm, by: Roger Costello(Roger)
Neil,
Thanks for the generous offer! You have mail. The circumstances in which my V8 stalls with the switch removed are A/C off, engine warm and idling in drive, turn wheel to lock and bingo it stalls. A/C on it does not happen. It's such a common feature of Toyota's Power Steering systems I'm sure they don't fit the idle up system for fun. As you've had no problems after removing it perhaps we should put the RYCO p/n up as a fix to try first for readers. I think the air fitting type tapered bung cost less than $2 last time I bought one. I am one of those sad people who wants to replace it with the factory part because it will bug me if I don't. The rest of you are free to save $168 and feel righteously happy thanks to Neil's excellent suggestion.
Wednesday, September 07, 2005 - 09:46 pm, by: Roger Costello(Roger)
Peter I have tried but it is just about impossible to photograph on a V8 and the EPC diagrams are not much help either. If you follow the high pressure hose up to the pump you will find it bolted to a union on which the switch is mounted. It is cylindrical, metal with a plastic molded section that has two vacuum hoses connected to it. Where it sits on a V8 it is practically invisible buried behind hoses and cables. If someone has an engine out they might be able to get a picture that makes sense.
Wednesday, September 07, 2005 - 11:53 pm, by: Cliff Newton(Tiger_x)
I just noticed tonight that I have a very small leak ( more like a sweat ) on my p/s pump. Mine is visible from the outside and is coming from the top connection at pump. All hoses are tight and the leak doesn't appear to be coming from the hose. Its the fitting the hose is connected to is where the leak is coming from. I will post a pic to explain it better. Does anyone know if there is a seal for this part? Cheers, Cliff
Thursday, September 08, 2005 - 12:22 am, by: Emanuel Spinola(Manny)
Removing that top/middle bolt allows that metal low pressure pump supply junction to separate from the pump body and will reveal an o-ring which seals it - it's the most common cause of a TT power steer pump seeping. The o-ring is readily available OEM from Toyota if you don't want to chance the aftermarket Russian Roulette options.
Thursday, September 08, 2005 - 12:29 am, by: Roger Costello(Roger)
Cliff, It is probably worthwhile doing the full reseal fairly soon though as if that one has gone it's companions are probably a bit tired as well. The Planet Soarer Tutorial is excellent:
Manny, Thanks for the Photo. Cliff you photo shows the TT location of the Valve Assy in the bottom left of the frame. It's the got the blob of blue paint just above the threaded section.
Thursday, September 08, 2005 - 03:56 pm, by: Alvar Scott(Alvar)
I've just overhauled my p/s pump, and it was a job from Hell! 10 minutes with a hammer to get pulley nut off...then blow-torch to get pulley off (I kid you not!). Now it's all back together, the engine surges. Do you guys think the "bung the hole up" trick mentioned above would calm my engine down? I feel like a boy racer sitting at traffic lights with the engine blipping itself from idle to 2500rpm.