PAS pump leak

#1
NADA 3500S, LHD.

My PAS pump leaked a few drops each day. It was coming from the seal. I removed the pump (non-trivial and very messy) and replaced the seal with the two-lip part that is now being supplied. After buttoning everything up, it still leaks, about the same amount and from the same place. Pulled it again. The shaft is very clean, has a kind of matte finish in the area of the seal. There is a single shiny ring from the old seal and two much fainter rings from the new seal. None of the rings seem to indicate wear, they are just polished areas. Bearings are tight. No evidence of leaks from the couplings or the pump body. There was a lot of fluid around the ball bearing.

Other suggestions? Is a drop or three a day something that you just have to live with?

gbvona
 
#3
My pump leaked from the low pressure pipe banjo fitting connection. There is a square section 'O' ring that fits in a recess there which gets hard and leaks over time. A proper size replacement doesn't seem to exist. Even a pump rebuild seal kit doesn't contain it. I found a very close fit alternative and assembled with PTFE tape and gasket cement (carefully as to not contaminate the fluid). It fixed the problem and I have been leak free for a few years now.
 
#4
PAS very noisy, losing much fluid

Hello Rover P6 professionals.
hello gbvona,


did you find the problem on your NADA? I have the same problem now, starting a few weeks ago.

After I got my car back from garage I did intensive test driving the last days/weeks. the car was perfect. (just BW35 reverse gear is very rough)

PAS problem:
- it started slowly, with some noise during the first minutes of driving (like a howling)
- this is noise also appears, if the car is standing with the engine running.
- If I push the acceleartor during the driving, the noise gets faster and little bit louder. (PAS fan belt?)
- also, it started to lose some oil (droping from the back / middle of the front valance)
but, after some kilometers it was okay, perfect PAS steering, superb to steer.

today, its worst.
- the car is losing much red oil, the PAS fluid reservoir was now just "half full" (1 week ago, it was full)
- some small bubbles in PAS reservoir
- the noise is very loud screaming/howling (hard to discribe, but its not a hissing)
- there is no servo assistance now (steering wheel is hard to move - like car in IGN on, but motor off position)

The PAS high pressure tubes were exchanged 1 year ago.

could it be the servo pump? (=noise) (fan belt?)
Of course, there must be a leak somewhere, becaue of the major oil loss.

can anyone give me an advice, before I start the car again?
thank you very much, kind regards, richard
 

PeterZRH

Well-Known Member
#5
Gentlemen, if you have PAS in a NADA, can I please politely ask for some hi-res pictures of your engine bay layout so I can locates all the clips etc close as possible. I'm doing a LHD retrofit currently and it would help a lot.
 
#6
PeterZRH said:
Gentlemen, if you have PAS in a NADA, can I please politely ask for some hi-res pictures of your engine bay layout so I can locates all the clips etc close as possible. I'm doing a LHD retrofit currently and it would help a lot.
Hi Peter,
I just can take some pics from my NADA reservoir - maybe next week - I will upload here in this section. okay? :D
are you from germany? because you wrote dreitausend fünf?
I am from austria
kind regards
richard
 

colnerov

Well-Known Member
#8
Hi, sagegreen, The howling you can hear is air cavitation in the fluid. This has two causes but in
your case the fluid level is low so the pump is drawing air as well as fluid. There is a hydraulic hose
runs across the front valance fixed to the radiator support bar, I would say that is where the leak is.
Just because the hose is not very old doesn't mean it can't be leaking. It has either chaffed through
at a clip or against the edge of the support bar.

Colin
 
#9
PeterZRH said:
Thank you. Wonderful. Whereabouts are you in AT? I'm based just outside Zürich.
Griazi in die Schweiz :D
you are welcome. Should I first scan you pics of the RESERVOIR and PIPES/TUBES from the Rover parts Catalogue and the Rover Workshop Manual/german language version? would this a help for you?
I am in Salzburg. Österreich
kind regards, servus, Richard
 
#10
colnerov said:
Hi, sagegreen, The howling you can hear is air cavitation in the fluid. This has two causes but in
your case the fluid level is low so the pump is drawing air as well as fluid. There is a hydraulic hose
runs across the front valance fixed to the radiator support bar, I would say that is where the leak is.
Just because the hose is not very old doesn't mean it can't be leaking. It has either chaffed through
at a clip or against the edge of the support bar.

Colin
Hi dear Colin, thank you very much for response. I hope its just a leak in the hydraulic hose, so maybe I can repair** it by myself before my car will stay inside during the winter

**with advices from you guys
QUESTION: does it make sense to take down the front valance for a better access? what do you think? :D

Richard
 

colnerov

Well-Known Member
#11
Hi, The hydraulic oil pipes because of the position of the components end up doing a complete
lap of the engine bay. Because yours is a LHD the one that goes across the front is probably the
one that goes from the reservoir to the pump. This where the air is getting in because it's
slightly easier for the pump to draw air than fluid and why it leaks when not running. If it was the
high pressure line it would empty the system in short order. It might be easier to remove the rad
for two reasons it will give you more room to work to replace it and you won't get covered in oil.
As this hose is likely to be the low pressure supply pipe then you will find it's held on at each by
hose clips. So you just need to get an oil resistant hose of the right size to replace it.

Thinking about this over night in relation to your gearbox problem, check the oil cooler hoses to
the in rad cooler are not leaking which may be either or both.

Colin
 
#13
colnerov said:
Because yours is a LHD the one that goes across the front is probably the
one that goes from the reservoir to the pump. This where the air is getting in because it's
slightly easier for the pump to draw air than fluid and why it leaks when not running. If it was the
high pressure line it would empty the system in short order.
As this hose is likely to be the low pressure supply pipe then you will find it's held on at each by
hose clips. So you just need to get an oil resistant hose of the right size to replace it.

Thinking about this over night in relation to your gearbox problem, check the oil cooler hoses to
the in rad cooler are not leaking which may be either or both.

Colin
thank you very much dear colin.

I looked now to the car, because I tried to drive out of my garage. well, it must be a massive leak or maybe the connection between 2 pipes/tubes is not tight. fact is, I 2 days ago I filled circa 1,5 liter new servo fluid into the resorvoir. now, after 2 days (the car was not driven) nearly all of the oil dissapeared. its now on the floor of my garage....

Gearbox/oil cooler: hmmm, I will check this as soon as I can fix my PAS leak problem. but this is a good advice, because I never thought about this connection (oil cooler house in the radiator cooler)

thanks a lot for your support and help.... :) first I must clean my oily underground car park place, after this I will fill up PAS fluid again and drive out of the underground car park into daylight. then I can see more of this oily mess. well, as you mabye noticed in my other messages, there are no (old) rover (P5,p6,Sd1) workshops/specialists, no "real" old brit car professionals around 100 - 200 miles or more. I must study my workshop manual if I can repair/check this alone? :p
 
#14
PeterZRH said:
Thanks for the kind offer. If you don't know already then many but not all the component catelogue scans are available online: http://www.rover-classics.co.uk/pages/r ... llery.html

They are super hi-res too if you click on them.
oh, this good to know. cool. I did not know this before. vielen dank, thanks a lot. when you read my new message about my massive PAS leak problem, you will see that it is hard to get my car out of "Tiefgarage" at the moment. so I will take the pics of reservoir first inside garage with flash. as soon as I can get my car out of dark garage, I will shoot fotos during daylight. I hope this will happen soon.

ric
 
#16
colnerov said:
Hi, sagegreen, The howling you can hear is air cavitation in the fluid. This has two causes but in
your case the fluid level is low so the pump is drawing air as well as fluid. There is a hydraulic hose
runs across the front valance fixed to the radiator support bar, I would say that is where the leak is.
Just because the hose is not very old doesn't mean it can't be leaking. It has either chaffed through
at a clip or against the edge of the support bar.

Colin
Hi,

today I looked inside the front valance bars and behind the left front wing - looking for the servo pump.

A:) it seems, that the fluid is coming from servo pump/hose, (see picture, the hose connected to the pump is very oily) and runs from this point down (in a DROP-SHAPE a long the hose) to the centre of the front valance. So, my first thougt was, the hose would have a leak in the middle of the front valance. But I think now, this is not the case.

correction:
B:)the hose which comes from the servo pump and runs down to the middle of the front valance, the left side is oily and greasy. the rights side hose is clean and dry.

Question:
what could be the reason for this leak? maybe a loose connection with the hose-clamp on servo pump? (see foto of oily hose - red arrow)
what can I do (DIY) in this case? If I fix this hose in a correct way, are there any other things I must do after this? like bleeding the steering idler? Any good advice and idea is very welcome.
thank you

kind regards, Richard
 

Attachments

colnerov

Well-Known Member
#18
Hi, If it's the hose coming from the reservoir that is leaking then change it. it's just low
pressure oil hose, don't bother trying to join it just replace the whole length. If it's the
pipe going from the pump to steering box (idler as you call it) then that is a high pressure
(circa 400 psi) then you need to get it re hosed by a hydraulic company, they should be able
to re use your original fittings. To bleed it afterwards just fill the reservoir, start the engine,
top up the reservoir again, then turn the steering from lock to lock, It will be heavy and a
bit noisy at first but get better after a couple of lock to locks, recheck reservoir and top up
again and a day or so later.

Colin
 
#19
Updating a very long process (I'm the guy who started the thread).

Since my ride was about 47 years old I resolved to change out all of the power steering hoses, in the even that they could be contributing to the leak.

Easy to say, not so simple to do (1971 NADA 3500S, lhd). Material is readily available from the usual sources, including the high-pressure hose. The high-pressure hose and the return hose to the reservoir are not so difficult, hardest part is getting the hoses without fittings over the nipples. Hint: Don't do it in cold weather.

The return hose from the reservoir to the pump is a nasty bit because of the routing. You have to take off the front valence to get at it. That being said, it's straightforward but tedious. For access I also removed the radiator. Here's a hint: DO NOT cut the hose to the pump until the radiator is back in place. the hose has to curl around the edges of the radiator. Don't ask how I found this out.

I also put the pump on the bench and checked it out thoroughly for flatness on the sealing surfaces. One thing I found was that the sealing washers in the repair kit from a certain vendor were undersized. This is both for the large o-ring around the rotor and the square o-ring washer that seals the input banjo on the return line. Fortunately I had saved the original washers and put them back in.

After tightening everything up, with some optimism I filled the reservoir.

The next morning there was about a 6" puddle of red on the garage floor. It was dripping off the bottom of the pump.

Long story short, it turns out that I had re-used the original Jubilee clips on the return hose to the pump. Vicious tightening of the one on the pump still did not prevent a leakage around the banjo and onto the pump. I replaced the clip with a new one and the leakage stopped.

Moral: Always use new clips. They are cheap.

gbvona
 
#20
PAS very noisy, losing much fluid - Problem solved


Dear Rover friends,

just to inform you, the Problem with the PAS on my car was solved a few weeks later in 2015 , the rason was very simple. the mechanic just changed 1 of those PAS hoses / high pressure hoses. the other one was still the old one, which was leaking.

regards
Richard


Hello Rover P6 professionals.
hello gbvona,


did you find the problem on your NADA? I have the same problem now, starting a few weeks ago.

After I got my car back from garage I did intensive test driving the last days/weeks. the car was perfect. (just BW35 reverse gear is very rough)

PAS problem:
- it started slowly, with some noise during the first minutes of driving (like a howling)
- this is noise also appears, if the car is standing with the engine running.
- If I push the acceleartor during the driving, the noise gets faster and little bit louder. (PAS fan belt?)
- also, it started to lose some oil (droping from the back / middle of the front valance)
but, after some kilometers it was okay, perfect PAS steering, superb to steer.

today, its worst.
- the car is losing much red oil, the PAS fluid reservoir was now just "half full" (1 week ago, it was full)
- some small bubbles in PAS reservoir
- the noise is very loud screaming/howling (hard to discribe, but its not a hissing)
- there is no servo assistance now (steering wheel is hard to move - like car in IGN on, but motor off position)

The PAS high pressure tubes were exchanged 1 year ago.

could it be the servo pump? (=noise) (fan belt?)
Of course, there must be a leak somewhere, becaue of the major oil loss.

can anyone give me an advice, before I start the car again?
thank you very much, kind regards, richard
 
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