Inline oil filter for PAS system?

[Maverik]

ok, just forked out for a shiney, spanking new PAS box from Adwest for my 90, now I don't know how fooked my PAS pump is (no history), so from stopping me taking my new PAS box out prematurely I was wondering about putting a small inline oil filter into the system, anyone any thoughts?

I was looking at maybe using a small engine oil filter and housing from a. n. other car...

Cheers

Mav

[Mr Ian]

Hi good idea BUT can the filter handle the line pressures, it can get quite high on the pressure side and putting the filter on the return side kind of defeats the object. Did'nt David Llama have a reservoir with integral filter, much better approach. Regards Ian Ashcroft

[Maverik]

Hi good idea BUT can the filter handle the line pressures, it can get quite high on the pressure side and putting the filter on the return side kind of defeats the object. Did'nt David Llama have a reservoir with integral filter, much better approach. Regards Ian Ashcroft

107 squid for his integrated reservoir/filter... great idea... but oucha...

That idea also just uses a filter on the low pressure side, I guess it wont stop a direct failure, but it will mitigate partical contamination i guess.

Anyone idea on what pressure the working system is?

[zim]

http://www.llama4x4.com/page3.htm

David posted on here not too long ago about it if you have a search

G

[western]

& provided it doesn't cause the PAS pump any restrictions in flow rate.

[Gremlin]

Did'nt old rangie ones have a filter in the reservior?? Why they stopped using it is beyond me!

G

[Turbocharger]

I'd expect that filtering on the return side would be just as effective in the long term, and you could flush the rest of the system with clean oil first.

[M&S]

I'd expect that filtering on the return side would be just as effective in the long term, and you could flush the rest of the system with clean oil first.

I agree. This is also the "norm" whith most common hydraulic systems.

[M&S]

& provided it doesn't cause the PAS pump any restrictions in flow rate.

The filter system would need a bypass valve for when it became blocked.

[Daan]

I did think about the filter idea, but I reckon a magnet in the reservoir would be much more effective. I havent quite looked at this, and because there is no drain plug, the usual way is not possible. But it cant be that hard to incorporate methinks.

daan

[jbs]

I've bought a couple of rare earth magnets off of e-bay to try this in the PAS Fluid pot, I'm sure if they do work then great but if they don't well nothing really lost to be honest just a bit of time thats all

John

[Maverik]

Magnets are a good idea, but not knowing the internals of the PAS pump and box, do they contain brass? most hydraulic pumps I've played with have brass bits. The advantage of a filter is it takes out the mud, rubber, brass and everything else that finds its way into the system...

I just found this - think it would get by? linky

Does dave at Llama do forum discounts? - they do look rather good.

[Aragorn]

FWIW the pump from my A4 when i had it out had "100 Bar" stamped on its ID tag. I presume thats the maximum pressure the pump can supply, but it gives an idea of the maximum working pressure of the system?

[Aragorn]

The Jag filter looks perfect, just ensure you find out where its supposed to go, as i doubt that spin on cartridge will take 100Bar!

[Maverik]

The Jag filter looks perfect, just ensure you find out where its supposed to go, as i doubt that spin on cartridge will take 100Bar!

Aye - for that jag filter I was thinking about putting it into the low pressure side so you don't have the faff of interupting the high pressure system.

I have just found an RRC resovoir with a filter in it, anyone know why these where phased out?

[David_LLAMA4x4]

Forget putting the filter in the pressure side - a filter that can cope with up to 120 bar ( that's about 1700psi!!! ) is not going to be a neat little spin on jobby!

The idea of the integral reservoir is that it filters whatever is going down to the pump thus keeping the system clean and any carp in the filter or reservoir not through the pump and box.

Long term a filter in the return will be great once it have cleaned out what is already in there... buy the Jag one andd put it in the return pipe. Be very careful what hose you sue to join it up as ther are only a couple of rubber hoses that will take ATF properly and the braided teflon that is best for the job can't be closed with a Jubille clip it needs a swaged fitting....

I have got 3/8" and 1/2" rubber hose that is as good as rubber is ever going to be for ATF at about £17 a metre.....

David

[Bush65]

I'd expect that filtering on the return side would be just as effective in the long term, and you could flush the rest of the system with clean oil first.

I agree. This is also the "norm" whith most common hydraulic systems.

Might be the norm where you are!

Only found on cheap and nasty systems - or perhaps on expensive, but still nasty systems built by those that don't know better.

Most hydraulic systems don't like large back pressure in return lines, and so return line filters by necessity are large micron rating, which is OK for filtering large particles such as result from mechanical failure of components.

40 or more years ago, it was found that normal metallic wear particles from hydraulic components (like pumps and motors) include many that are much less than 10 micron in size. Return line filters don't remove these from the fluid, so they continue to be recirculated and their presence leads to much more rapid wear.

The solution found for removing those particles was to install Absolute 3 micron, pressure line filters. With these, the initial filters may block quickly, until the fluid is cleaned (new fluid from drums often contain considerable contaminants that can block Abs 3 micron filters), then component life becomes much greater. Following this it was found that reservoir breathers needed much better filtration, leading to use of spin on filters for breathers.

Hydraulic systems that are large enough, will have separate fluid conditioning circuits whose function is to just filter and cool. These overcome the pressure drop due to pressure line filters in the main circuits.

Engines also suffer from soot and wear particles contaminating the lube oil, which is why bypass filter systems are used. The centrifugal filters such as used on the TD5 engine will remove very small micron particles that escape from conventional filter media.

Getting back on topic!

What David at Llama4x4 has developed, certainly has it use/benefits.

An average power steering system is mediocre at best, and may not have enough capacity to utilise a return line filter, let alone one in the pressure line - more so with larger tyres fitted and or water around stretched drive belts.

Since the system spends most time doing little (while we are steering straight ahead), it might be worth considering if a bypass filtration system is practical or worthwhile.

[piper109]

You might find this link interesting. I have seen people use them on either the suction line or return line of power steering systems. They are basically made to be used on cooling lines of automatic transmissions.

Magnefine is one, Filtran is another.

Steve

http://cgi.ebay.com/ebaymotors/Magnefine-3-8-Inline-Magnetic-Transmission-PS-Filter_W0QQcmdZViewItemQQcategoryZ33662QQitemZ150416186560#vi-content

[Maverik]

Hmmm... ok, I was bleeding my PAS system the other day and peered into the resevoir, there appears to be a steel plate sat at the bottom of it, look like its come kind of baffle arrangment sat in the bottom of the bottle, anyone know anything about it?

[lrfarmer]

Hmmm... ok, I was bleeding my PAS system the other day and peered into the resevoir, there appears to be a steel plate sat at the bottom of it, look like its come kind of baffle arrangment sat in the bottom of the bottle, anyone know anything about it?

i've alwes thort that was just to stop it blowing oil out the lid if opened with the engine running

[Maverik]

Taken from another topic, these guys look like the right people to talk to on the subject:

Filter people

[Bush65]

Taken from another topic, these guys look like the right people to talk to on the subject:

Filter people

From that page, note that none give filtration ratings (some say they are strainers) and some have no pressure rating (some 25 psi).

Strainers are used on the suction side of pumps (between reservoir and pump) to prevent large particles (nuts, screws, etc.) damaging the pump. Any better filtration in the suction line can create too high of a pressure drop and lead to pump cavitation in hydraulic systems - Llama4x4 use a better filter, which demonstrates what is possible with the rover P.S. system.

Those filters certainly won't be suitable to use in the delivery line between the pump and steering box - not suitable for the pressure.

Be careful creating too much pressure drop in return line from steering box to reservoir - without knowing more of the box internals, it may cause the seals to leak.

[rick]

You might find this link interesting. I have seen people use them on either the suction line or return line of power steering systems. They are basically made to be used on cooling lines of automatic transmissions.

Magnefine is one, Filtran is another.

Steve

The couple of times I've had to replace a steering rack in the past a Magnefine filter was a condition of warranty (and provided) by the rebuilder.

[David_LLAMA4x4]

A magnet will do the ferrous filtering well - but limps of crud, foreign bodies and nits of rubber falling off the inside of unsuitable hose that has been used anyway will all flow staright past.

This thread seems to be doing the 'Land Rover thing' - by this I mean trying to work hard and bypass an established 'correct and efficient' method of doing something instead of just accepting that precident as a working model and embracing it! Probably not saving any money long term or indeed having a product that works as well as it should.

Guess why I put the filter in the reservoir on the feed to the pump side?? 'caise that is where it is supposed to go!!!

David

[Maverik]

A magnet will do the ferrous filtering well - but limps of crud, foreign bodies and nits of rubber falling off the inside of unsuitable hose that has been used anyway will all flow staright past.

This thread seems to be doing the 'Land Rover thing' - by this I mean trying to work hard and bypass an established 'correct and efficient' method of doing something instead of just accepting that precident as a working model and embracing it! Probably not saving any money long term or indeed having a product that works as well as it should.

Guess why I put the filter in the reservoir on the feed to the pump side?? 'caise that is where it is supposed to go!!!

David

Totally agree, Its probably already wasted my time and everyone elses, but a few reasons why its still up for disscusion...

- established doesn't always mean its correct and efficient

- searching for a cheaper alternative to what you produce (short term anyway!)

- maybe work out something that improves on whats there is already, we're all (mostly) enthusiasts here so why not speculate?

- Unfortunatly I'm one to play devils advocate, why not try something else?

If idea's like this where not air'd then we wouldn't be doing what we do.