PAS cooler upgrade

[Westy]

Hi guys.

After fitting my oil cooler last weekend I started to think about the PAS system as every time I'm under the car I can see the rusty, perishing PAS pipes. I know it's pretty easy to boil the PAS fluid on a track day within a few laps and also just how expensive new PAS pipes can be when they need replacing.

So I was thinking, If I fitted a cooler, can I do away with the rusty pipes and just run some new rubber/silicone replacements and bin the metal pipes? Also does anyone here actually run a PAS cooler already (Prawn maybe) as I've not seen much about them?

From my brief google research I've found a fair bit of info and kits in the states but not much in the UK. Any recommendations to cores or kits?

 

[<tuffty/>]

Hi guys.

After fitting my oil cooler last weekend I started to think about the PAS system as every time I'm under the car I can see the rusty, perishing PAS pipes. I know it's pretty easy to boil the PAS fluid on a track day within a few laps and also just how expensive new PAS pipes can be when they need replacing.

So I was thinking, If I fitted a cooler, can I do away with the rusty pipes and just run some new rubber/silicone replacements and bin the metal pipes? Also does anyone here actually run a PAS cooler already (Prawn maybe) as I've not seen much about them?

From my brief google research I've found a fair bit of info and kits in the states but not much in the UK. Any recommendations to cores or kits?

Unless using high pressure hose etc then you will need the metal ones still... its still high pressure hydraulics so you would need to get lines made up anyway... can bin off most of the clutter at least so its a worthwhile project...

Welly got his lines fixed by a company local to me so I would imagine a hydraulics specialist would be able to sort the lines if you gave them the dimensions

<tuffty/>

 

[Scullies]

Have you seen those transmission oil coolers that are tube shaped with fins around it? I think that might work, just need to find a place to fit it I guess

 

[Westy]

Unless using high pressure hose etc then you will need the metal ones still... its still high pressure hydraulics so you would need to get lines made up anyway... can bin off most of the clutter at least so its a worthwhile project...

Welly got his lines fixed by a company local to me so I would imagine a hydraulics specialist would be able to sort the lines if you gave them the dimensions

<tuffty/>

If you look at some of the pics of setups online they all seem to be using rubber hose to the core that tends to get mounted infront of the rad or FMIC. I was thinking 2 birds with 1 stone.

I need to have a proper look at the route the current pipes take and see if there's a suitable cheapish solution.

 

[superkarl]

yeh the hose they use are same sort you use for an oil cooler, obv it has to hold pressure and be resistant to oil.
The cooler part of the OE system IS those hard corroding metal pipes.

 

[<tuffty/>]

If you look at some of the pics of setups online they all seem to be using rubber hose to the core that tends to get mounted infront of the rad or FMIC. I was thinking 2 birds with 1 stone.

I need to have a proper look at the route the current pipes take and see if there's a suitable cheapish solution.

Maybe they fit them to the return but the feed is hydraulic pressure so the hose will need to be rated as such (not sure of the actual pressure but its 100's of psi)

<tuffty/>

 

[<tuffty/>]

As Karl said, all that metal pipe nonsense is the actual cooler... fitting a matrix of some description and simplifying the existing high pressure side may cost a little initially but ultimately last and be more reliable

As long as the rubber hoses are rated accordingly then no reason not to use rubber...

<tuffty/>

 

[Westy]

That's the standard cooler! Blimey, no wonder it boils up easily.

Tuffty, any idea what's on Bills race car?

I'll do some more reading, thanks lads.

 

[superkarl]

That's the standard cooler! Blimey, no wonder it boils up easily.

Tuffty, any idea what's on Bills race car?

I'll do some more reading, thanks lads.

its why it goes back and forth on it self before returning. Just relies on little airflow it gets and the heat exchange through the long metal pipe.

everytime im under my car they do my head in. especially since i didnt mount them very well after fitting my FMIC.

 

[<tuffty/>]

That's the standard cooler! Blimey, no wonder it boils up easily.

Tuffty, any idea what's on Bills race car?

I'll do some more reading, thanks lads.

std ibiza pipes on Bills... he has ****** his pas fluid but that was from lack of shielding on the rack

<tuffty/>

 

[Westy]

So even bill doesn't bother?! Wonder just how worth while a mod it would be then If his race car doesn't require one.

 

[ScottD3]

So even bill doesn't bother?! Wonder just how worth while a mod it would be then If his race car doesn't require one.

Try it?
Fit a temp gauge before and then fit a cooler?

 

[<tuffty/>]

Ibiza pipes are simpler from memory... tbh I think the issue is more due to the relationship of DP and rack... better heat shielding and heat wrap on DP goes a long way to prevent this from occurring... of course if you are looking to replace the metal pipe as its leaking then great but not sure how widespread a mod this is in VAG circles... vortex maybe worth a search...

<tuffty/>

 

[Westy]

Ibiza pipes are simpler from memory... tbh I think the issue is more due to the relationship of DP and rack... better heat shielding and heat wrap on DP goes a long way to prevent this from occurring... of course if you are looking to replace the metal pipe as its leaking then great but not sure how widespread a mod this is in VAG circles... vortex maybe worth a search...

<tuffty/>

Hmmm. Like I said I've seen some yank setups on A4s (I'll post links when off my phone) and they've mounted them infront of their rad or FMIC and have hoses running off of them.

 

[kwistof]

My metal pipes are on there way also....I'm surprised the rust is keeping all the pressure from releasing!

Sort of serves me right for running years without under belly pans

 

[Scullies]

I have been brain storming relocating the P/S reservoir after my mates TT caught on fire after the return line burst - luckily he saved it before to much damage was done. LHD cars have this long hard line oil return pipe that goes from the rack (gearbox side) across the firewall and does some crazy turns to avoid DP and propshaft, up the engine bay (cambelt side) then is crimped to the rubber line that feeds the reservoir. This is where the pipe splits and sprays nice hot P/S fluid onto your nice hot manifold and DP.

Anyways mine is LHD, so the rack is opposite to RHD - DUH!!
My idea has been to remove the the oil return line (#7) cut the metal pipe near the rack outlet and get a rubber hose crimped on.



This hose will run up over the gearbox and into a different type of reservoir. Something like this.



The reservoir will be mounted somewhere on the gearbox side of the engine bay. Now the P/S pump oil inlet (#3) would be replaced with suitable hose that runs from the new relocated reservoir, into a cooler of some sorts that its mounted in the SMIC position, then feeds the P/S pump. This would leave me with a lot more space on the cambelt side.

As far as I can see there is no real pressure in these two lines #3 % #7, so it should be safe to have a cooler fitted on one of them.

I know #4 is the line in question but I think a cooler that would withstand the pressure in the line would be a bit pricey.

 

[Westy]

My metal pipes are on there way also....I'm surprised the rust is keeping all the pressure from releasing!

Sort of serves me right for running years without under belly pans

I ditched my under tray about 18 months ago. Probably get slightly better cooling benefits without it but more exposure to the elements.

 

[kwistof]

I ditched my under tray about 18 months ago. Probably get slightly better cooling benefits without it but more exposure to the elements.

I lost my middle one about 3 years ago and this winter both the sides got smashed in so I ripped those off! lol

Yeah, very true about the cooling benefits - but I also wonder if it creates any extra drag when hitting high speeds, and by how much....

I don't expect anyone has a spare wind tunnel? lol

 

[superkarl]

I have been brain storming relocating the P/S reservoir after my mates TT caught on fire after the return line burst - luckily he saved it before to much damage was done. LHD cars have this long hard line oil return pipe that goes from the rack (gearbox side) across the firewall and does some crazy turns to avoid DP and propshaft, up the engine bay (cambelt side) then is crimped to the rubber line that feeds the reservoir. This is where the pipe splits and sprays nice hot P/S fluid onto your nice hot manifold and DP.

Anyways mine is LHD, so the rack is opposite to RHD - DUH!!
My idea has been to remove the the oil return line (#7) cut the metal pipe near the rack outlet and get a rubber hose crimped on.

View attachment 16455

This hose will run up over the gearbox and into a different type of reservoir. Something like this.

View attachment 16456

The reservoir will be mounted somewhere on the gearbox side of the engine bay. Now the P/S pump oil inlet (#3) would be replaced with suitable hose that runs from the new relocated reservoir, into a cooler of some sorts that its mounted in the SMIC position, then feeds the P/S pump. This would leave me with a lot more space on the cambelt side.

As far as I can see there is no real pressure in these two lines #3 % #7, so it should be safe to have a cooler fitted on one of them.

I know #6 is the line in question but I think a cooler that would withstand the pressure in the line would be a bit pricey.

would you not want the cooler on the high pressure line, as the high pressure fluid is what gets hot.
I see your idea, would that mean you could get rid of number 6 then?

 

[Scullies]

yeah, looking at it again, #6 could be removed as I cant see why there would be massive pressure there as it feeds into the reservoir. I think there is only pressure in #4 between the P/S pump and rack.

 

[Prawn]

Good topic dude.

As many know, I used to suffer quite badly from PAS overheating, every track session would see the fluid boil and the steering go notchy.

I now don't have any issues with it boiling at all, despite going considerably faster than i used to.

I'm not sure whether this is down to all the additional heat shielding I've added to the rack when doing my ko4 conversion, or down to having made the car actually handle properly with decent components and geo, rather than forcing everything to work ultra hard.

Whichever it is, the problem is solved, and like Bill, I just run standard lines now without issue.

I'd say the issue is elsewhere, whether it's turbo related heat, or over active steering inputs due to fighting against a sub optimal setup.

 

[Westy]

Good topic dude.

As many know, I used to suffer quite badly from PAS overheating, every track session would see the fluid boil and the steering go notchy.

I now don't have any issues with it boiling at all, despite going considerably faster than i used to.

I'm not sure whether this is down to all the additional heat shielding I've added to the rack when doing my ko4 conversion, or down to having made the car actually handle properly with decent components and geo, rather than forcing everything to work ultra hard.

Whichever it is, the problem is solved, and like Bill, I just run standard lines now without issue.

I'd say the issue is elsewhere, whether it's turbo related heat, or over active steering inputs due to fighting against a sub optimal setup.

Thank for your input matey. I've never had the issue myself but I don't go too mad on track. I was mainly looking at options when my PAS pipes eventually need replacing. I've been getting all cooling obsessed recently

 

[s3dave]

Yeah #6 is low pressure side so ideal for a cooler, mine is made of copper now...

 

[Prawn]

Is pipe 6 an additional cooling loop on the s3? Mine just had the steel feed to the rack then a return straight up to the reservoir.

Pipes 3 and 7 in The above are fine for a cooler in theory, but 3 is a gravity feed to the pump, so I think you'd be best off adding a cooler in te pumped return (7) of you were going to.
I
still have a PAS cooler core and hose for mine, but until I know I need it I'm choosing not to add anther source of fluid leaks!

 

[Westy]

Some good reading here:

VWVortex.com - Power steering cooler hose

It looks like the A4 has a bigger cooling loop of metal pipe that is mounted infront of the rad. Wonder if fitting an A4 cooler in place of the A3/S3 one (if possible) would be a beneficial upgrade...

 

[Ste_Nova]

I ditched my under tray about 18 months ago. Probably get slightly better cooling benefits without it but more exposure to the elements.

its better with it on

 

[Westy]

its better with it on

Any proof?

 

[Westy]

Great read here regarding setting up a PAS cooling system:

http://www.pscmotorsports.com/pdf/tech/cooler_mounting.pdf

 

[<tuffty/>]

Any proof?

All the cars I have seen come in with it missing have all sorts of corrosion etc... ones where its fitted don't suffer anywhere near as bad....

The LCR and TT have a tray that pretty much covers the whole underside of the engine bay... newer VAGs have plastic under trays along the underside of the body too... aero dynamics, less drag, better economy etc...

Same reason this is done on race cars too...

<tuffty/>

 

[kwistof]

aero dynamics, less drag, better economy etc...

Same reason this is done on race cars too...

<tuffty/>

Westy you could have got into the 12s with a belly pan lol

 

[Westy]

I'm talking proof of cooling not proof of aerodynamics

 

[<tuffty/>]

I'm talking proof of cooling not proof of aerodynamics

there is a kind of NACA duct in the under tray that looks like its there to allow air to be drawn through from the front of the engine bay... whether this is there to improve flow over the PAS pipes I don't know but personally I would rather run one than not purely for the protection against the elements...

Anything that needs to be seriously cooled needs to be in the airstream IMO... oil cooler, FMIC etc... all fitted where airflow is...

<tuffty/>

 

[Westy]

Ok ok I see your point matey.

I mainly binned off my under tray due to a lot of the fixings being hacked off due to other mods. I should really look into a custom undertray made from a thin sheet of Ali.

Back on subject though. I'm now wondering if there's any way and benefit of getting the PAS cooling loop out in the air a bit more.

 

[<tuffty/>]

Cooling hot stuff is always a good idea

<tuffty/>

 

[ScottD3]

there is a kind of NACA duct in the under tray that looks like its there to allow air to be drawn through from the front of the engine bay... whether this is there to improve flow over the PAS pipes I don't know but personally I would rather run one than not purely for the protection against the elements...

Anything that needs to be seriously cooled needs to be in the airstream IMO... oil cooler, FMIC etc... all fitted where airflow is...

<tuffty/>

 

[<tuffty/>]

There you go then

<tuffty/>

 

[Scullies]

Ok ok I see your point matey.

I mainly binned off my under tray due to a lot of the fixings being hacked off due to other mods. I should really look into a custom undertray made from a thin sheet of Ali.

Back on subject though. I'm now wondering if there's any way and benefit of getting the PAS cooling loop out in the air a bit more.

what you need to do is, borrow a scooby bonnet scoop then fit it under your car to direct air onto the PAS lines