PAS Pump Outlet Fitting - Leak arrggh

amcdonald

Active Member
Hello

So everything connected up on my rebuilt engine, but not started up yet. Small coolant leak that I am hoping to fix with mouse milk, but much larger PAS leak at the pump outlet. The flared fitting looks odd to me for something going into a fitting like that but I checked out the pic on a couple of web sites and the LHD 578211 part pics in the manual and all show this flare to be correct. The pics are below.

Even with no pressure - pump not spinning, obviously, the fluid dribbles out of the fitting when its (very) tight. I can't really see how this can create a good seal. It is hard to see on the photo but on the pump side there is a raised flat ring that the flared pipe mates with (or not as the case may be). Is something AWOL?

Please help - any clues? I can't really get any further towards the break-in until this is fixed and I can progress onto the next problem.....

My new hose (also a strange fit in the engine bay but that's another story):
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Pump:
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The hose:
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Hi, That's the same type of fitting as brake pipes so it's more than capable of sealing. Is it the old pipe or the new pipe that's not sealing? If it's the old pipe then check the base of the flare on the pipe for cracks, it can happen sometimes. If it's the new pipe then nip the flare nut up so the pipe can turn with a little force, then turn it backwards and forwards so it can settle in to it's seat, like lapping it in. You can still check it for cracks as well because it's not unknown. If it leaks with both pipes then check the seat in the pump, it can leak with just a scratch on the cone.

Colin
 
Hi

In a muppet move, I chucked the old one out years ago. Even though there was nothing wrong with it except being a bit manky. It is odd as the pump fitting is flat, not like the brake joints that are matching tapers - I would have expected a mating tapered fitting inside the pump but that does not look like what is in it. Its just a ring so there's nothing much at all in terms of the touching faces
 
Is the pump off a V8 as I notice on Land Rover applications an O ring is listed for the pipe to pump
 
Some photos of my installation when I was having issues with the hydraulic hose not fitting. The hose fitting went straight into the pump body. I called the supplier about the fit of the hose which was hitting the chassis and was informed that I need to bend it to fit. Wasn’t impressed by that response TBH. I can’t recall if there is a separate tapered olive that could fall out if not careful? when nipped up are there still threads on the nut remaining? Note where the metal part of the new hose strikes the chassis.


 
Hi

Thanks for the pics. It’s a NADA V8 and yes that’s exactly the same hose as mine. There are threads still showing when it’s super tight and the fluid comes right out so with pressure I envisage a good squirt.

the pic of the old hose is useful as I don’t think the threaded nut is even long enough to mate the piece to my pump in its current state. So this likely indicates that during the rebuild the mystery olive went AWOL. This is about the only thing that makes sense.

I hope someone on here can confirm the diagnosis but now I have the problem of locating said item.
 
Hi

As this is a compression fitting I would expect a tapered metal insert of some sort. Unsurprisingly google is no help in this matter.
 
Hi all and a Happy New Year to everyone,

Guess that this is my area of expertise the power steering pump used on the P6 3500, early Range Rover, P5B and many other British built cars of the 60’s and 70’s are variations of the Hobourn Eaton Series 30 pump. The attached drawing is of a typical HE pump probably very similar to the P6 part, not sure now which pump part number is used on the P6 with out searching the archives at work. Does anyone have the HE number from the label on the pump. Anyway the company that I now work for purchased the manufacturing rights to the pump in the mid 1990’s hence way I have access to the OE drawings.
From the picture of the discharge port on Adrian’s vehicle I cannot clearly be sure if the orifice tube is missing or not. I would be surprised if it has fallen out as they are normally a light press fit into the cover.

If you look at the section view on the attached drawing of the control valve and orifice tube you will see how it should look, the part in question is HE 2837/.
If I remember correctly this is an aluminium part that has a orifice hole at one end that is sized to provide the correct amount of flow, the other end has the required cone for the sealing of the delivery tube/hose.

Two things that you should check on your replacement hose.
1). That it has the correct angle of flare, it should be an SAE 45 degree angle ( 90 degrees inclusive) and not the 37 degree JIC standard of flare used in industrial hydraulics and more common with hose companies.
2). That the tube nut used is the correct thread 5/8”-18 UNF and not metric M16-1.5 thread, both look similar to each other 18 tpi is 1.41 mm pitch. So with thread clearance you might be able to screw the M16 in to the pump but will go tight before clamping the tube flare.

If the orifice tube should be missing I should be able to find the drawing for it, unfortunately all these pump drawings are on old fashion microfilm, so will need scanning into electronic form.
 

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HI

thanks for the great info. Here are some better pics, attached. As you can see the mating surface is flat with if anything an angled surface going the other way on the ID of the metal ring.

the hose came from Wadhams.
 

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Picture 2 and 3 clearly show the orifice tube in the discharge port, so you have no missing parts. The 45 degree angle from the small centre flat diameter to the internal thread is the cone that the flare of the tube should seal on. If you look at the top of the cone where it is truncated by the flat top you can see a contact band has formed where a flared tube has been clamped to it. Ensure that this cone is not damaged and likewise with the flare on the tube.

Would of been nice if Wadhams had got the correct bend radius and length, have any other members had problems with leaks with these hoses.
 
Picture 2 and 3 clearly show the orifice tube in the discharge port, so you have no missing parts. The 45 degree angle from the small centre flat diameter to the internal thread is the cone that the flare of the tube should seal on. If you look at the top of the cone where it is truncated by the flat top you can see a contact band has formed where a flared tube has been clamped to it. Ensure that this cone is not damaged and likewise with the flare on the tube.

Would of been nice if Wadhams had got the correct bend radius and length, have any other members had problems with leaks with these hoses.
Thanks for sharing that detailed info, and your experience. The hose I have came from Wadhams, ok it doesn’t take much to bend it, but as you can see in my photo comparison they are quite different, so not even close IMO. Could do better on next batches.

Incorrect threads aside. The OP mentions that threads are still protruding from the housing so in theory at least they should be able to tighten the pipe taper onto the orifice taper you would think, unless the thread in the pump housing was not deep enough or perhaps the aluminium tapered seat has been extruded/compressed over the years making it shorter and not allowing the threads of the fitting to apply and sort of compression? in the drawing the bottom of the thread does seem indeed very close to the tapered edge of the orifice seat and perhaps any tolerance mismatch would show up here, perhaps if the OP filed the 1st thread off the fitting off it might allow more compression, perhaps the pipe tapered face is quite thin compared to original and all these tolerances stack up against the installer?

An engineering drawing of HE 2837 orifice would be handy reference if you are able to track it down ?
 
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Hi

okay, so this is like one of those pictures where one person looks at it and it’s a man with a big nose and someone else sees a bunch of carrots. I looked at my own pic again and then clear as day I saw the conical shape but only after you mentioned it!! I think my eyesight is too bad to be able to see it in the flesh. Anyhow I reckon the hose must have to be perfectly aligned as the mating surface looks very small. Or maybe the hose end is just too big so it might be bottoming out in some way, before a proper seal is achieved on the faces. Trial and error time.....
 
Yes the owner should ensure that the tube nut is clamping the flare of the tube onto the cone of the orifice tube insert. When the tube nut is tight it should not be possible to rotate the tube and no axial movement. There should be enough thread depth in the pump body to take the tube nut.
I should be able to obtain all the drawings for the pump if someone can provide the part number from the label on the side of the pump. I did have some notes at one time but not sure were the folder is now, I probably have an old pump around in storage.
 
Hello

So with the new confidence that the parts might actually mate together, I had another go at it. When I carefully held the new pipe as close to the center of the fitting as possible when tightening it up, I got a seal. Or at least I hope I have. The new part is just very finicky regarding installing it and I can’t quite see why. But I am hoping I am now onto the next problem (that has already appeared).
 
Could just be a large amount of clearance between the tube and tube nut allowing the tube to move off centre, but normally the flare will centre itself unless the tube is being deflected by say contact with the body or other components.
I will have a look for the pump drawing when back at this week.
Unfortunately all the tooling for the series 30 pump was destroyed about 15 years ago, so there is little chance of manufacturing new ones unless JLR Classic decided to finance a limited production run for the Range Rover Reborn program.
 
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I can never understand why it's easier to manufacture something that's "wrong" rather than "right", and if it isn't easier, (or cheaper) why can't they make it correctly in the first place, especially if they are working from a pattern . The pipe diameter looks bigger on the new one, which if that's the case, is probably why the curve isn't tight enough, and why it doesn't seal properly, and if it is the same size, then why not get the right bend in it.


V8 rear shock rubbers spring to mind, rubbers that won't fit to the sleeves provided.
 
Hi

The larger bend radius is a problem for the lower valance clearance (or lack thereof) but in my case I had it right forward on its brackets so that was not an issue.

I think JRL has it right on the first sentence as the pipe is too loose in the nut so you can align it wrong enough for the flare to not self center when the nut is tightened.

So the hose will work but it must be installed carefully not like typical compression stuff where if it’s on it’s on. I also made sure the hose was very slack without tension of twisting pushing it slightly off center when doing up the nut.
 
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