Defender Td5 PAS pump noise

[Guineafowl]

New pump (https://www.advancedfactors.co.uk/qvb101350-defender-90-110-td5-power-steering-pump-40250-p.asp) and both pipes changed. Old one was leaking a bit.

Did the LR workshop manual bleed procedure (run up to op temp, open steering box bleed valve). Dexron III fluid used.

The new pump is making a moaning sound which varies with engine speed.

Went through fault diagnosis in the same manual:
1. Check pressure pipe isn’t vibrating against body
2. Bleed system (did it again).
3. Do figure-8 manoeuvres.

Also, no leaks. Is it time to return the pump? Oddly, the fault diagnosis never mentions a faulty pump as a source of moaning noise.

 

[colnerov]

Sounds like cavitation. It's drawing air somewhere, check the connection from the reservoir and in it to make sure it's not partially blocked. Also run it from lock to lock and see if it improves.

 

[dave h 2]

As above, turn lock to lock several times allowing the pressure relief valve to operate, then let the air bubbles settle out. You may have to bleed again and top up. On older systems with the reservoir on the pump you could see the fizz inside.

 

[Guineafowl]

Feed pipe from reservoir to pump was changed too.

I’ve done some lock-to-lock, with wheels in the air and on the ground. Also the figure-8 stuff mentioned above.

If I (briefly) hold the steering on lock and rev the engine slightly, it sounds like I have a supercharger.

Might just try leaving it a bit, maybe a run into town, then bleed again. I don’t think the pump will last long, making a racket like that.

 

[Guineafowl]

Had another go.

1. Pressurised the reservoir and looked for leaks along the feed pipe and pump - none.
2. Flushed reservoir and blown through the feed pipe.
3. Removed pump and inspected, tested if it holds a vacuum between inlet/outlet - ok.
4. Put it all back together and re-bled. Took it for a blast along the main road.

Doing the lock-to-lock brings no air bubbles up. Time to return the pump, I think.

 

[reb78]

The original pumps on these came from Hobourn. I had a quick search of the usual suppliers - they used to be easier to find but would be worth a search to get proper OEM quality. I like AF for disco parts but they have less choice of quality with the defender and D2 parts and earlier.

 

[reb78]

Island 4x4 claim to have one but a. I don't necessarily believe them and b. if you do buy from them and have a problem... good luck....!

 

[Guineafowl]

The original pumps on these came from Hobourn. I had a quick search of the usual suppliers - they used to be easier to find but would be worth a search to get proper OEM quality. I like AF for disco parts but they have less choice of quality with the defender and D2 parts and earlier.

It looks like Hobourn went out of business, so no such thing as OEM, even if the part number has a G at the end.

AF were pretty good - said they’d never had a problem with their pumps, but get another one from wherever, fit it and return this one.

 

[Smallfry]

I worked for a while at Hobourn when they were at Strood in Kent. Very good QC. They moved to Skelmersdale or Warrington after I had left. They had been bought prior to this by Eaton, who were a US company. Eventually all manufacturing was moved to Brazil ISTR.

 

[Ubique]

The filter is part of the PS fluid reservoir, I'd suggest you change it - when I was in a LR dealers most 'noisy pumps' were caused by a restricted filter causing oil starvation, leading to excessive wear and more noise and more blockage of the filter...

 

[colnerov]

The filter is part of the PS fluid reservoir, I'd suggest you change it - when I was in a LR dealers most 'noisy pumps' were caused by a restricted filter causing oil starvation, leading to excessive wear and more noise and more blockage of the filter...

I would go along with that. On the buses we would sometimes find the filter in the reservoir would break up and a piece of the paper would fall and partially block the supply hole and so restrict the flow causing the cavitation. The Leyland National was worst for that because they were of monocoque construction and the whining would reverberate through the whole bus.

 

[ranchero]

Eaton, who were a US company

they still are. when i bled my PS the fluid had a lot of very fine bubbles in it it took a long time for them to come out

 

[Guineafowl]

The filter is part of the PS fluid reservoir, I'd suggest you change it - when I was in a LR dealers most 'noisy pumps' were caused by a restricted filter causing oil starvation, leading to excessive wear and more noise and more blockage of the filter...

I have flushed the PS reservoir, and was able to unscrew the filter and inspect it by turning it round inside - plastic mesh type, all clear.

Another pump fitted, still making noise. It’s something I’ve changed, because the old pump was silent, just leaking a bit. Could it be something to do with the new pipes - reservoir-to-pump and pump-to-box? New fluid is Granville ATF Dexron III.

Is the high pressure (pump-to-box) pipe meant to be rubber-mounted against the chassis? I’ve tried pushing it around. Grabbing it tightly does quieten the noise.

 

[Ubique]

Did you crimp any of the hoses? they have (in certain positions) flow attenuators and PTFE sleeves which if crushed will cause noise in the system. It's also possible that there is a restriction in the steering box (or pipes / hoses) due to residue from a failing pump...

It doesn't look like there are any intermediate insulators to me https://parts.jaguarlandroverclassic.com/parts/index/hierarchy/id/10.55852.56381/brand/land-rover/

 

[Guineafowl]

Did you crimp any of the hoses? they have (in certain positions) flow attenuators and PTFE sleeves which if crushed will cause noise in the system. It's also possible that there is a restriction in the steering box (or pipes / hoses) due to residue from a failing pump...

It doesn't look like there are any intermediate insulators to me https://parts.jaguarlandroverclassic.com/parts/index/hierarchy/id/10.55852.56381/brand/land-rover/

(That’s the Puma one you’ve linked there, but the Td5 one is similar). Useful website.

No - I had to cut 15mm off one end of the feed pipe, but that’s all.

Strange - it works fine despite the noise, and the old pump worked fine too. Just a leak from it mentioned on the MoT.

 

[Ubique]

I linked to the Td5 one first, then noticed the part number was for L316 so changed the link!

https://parts.jaguarlandroverclassic.com/parts/index/hierarchy/id/3.55727.56023/brand/land-rover/ for L315

Noise in PS is usually caused by pump, HP restriction causing relief valve operation, LP restriction (e.g. blocked return filter) or a damaged pipe/hose. From memory, the relief valve is in the steering box and would be my next item to check.

 

[Guineafowl]

I fitted two aftermarket pumps and they both made a racket, so were sent back. Original one made less noise, just leaked a bit.

I’m now planning to rebuild the original with this kit from RR steering:


Also planning to replace the bearing, which I believe is a 6302-2RS1 C3.

Any advice/words of encouragement?