# Power steering cooler hose



## 908AudiTT (Jul 24, 2012)

Hey guys, my cooler hose that's right under the radiator for the power steering fluid was leaking, so we fitted it with a small hose. Now it has no power steering, but the wheel turns when the car is moving. 

Do you think the pump is not sucking in the fluid due to loss of pressure in the tube?

Thanks!


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## Chickenman35 (Jul 28, 2006)

908AudiTT said:


> Hey guys, my cooler hose that's right under the radiator for the power steering fluid was leaking, so we fitted it with a small hose. Now it has no power steering, but the wheel turns when the car is moving.
> 
> Do you think the pump is not sucking in the fluid due to loss of pressure in the tube?
> 
> Thanks!


You probably got a lot of air in the system when you changed the hose.

You need to bleed the system of air.

Procedure:

1: With engine off check PS fluid level. Top up as required. ( Note: Use only VW/Audi approved PS Fluid. Pentosin is best )

2: Jack up front of car so that wheels are in the air. With engine off, turn the steering wheel lock to lock 10 times.

3: Recheck PS level and add as necessary.

4: With wheels still in air. Start engine and see if fluid level goes down. Add fluid as necessary.

5: Turn steering wheel lock to lock with engine running 10 times. Easy does it though when you hit lock. Do not let pump squeal !! have someone monitor the level while you turn wheel. Add fluid if necessary. You should now have your Power steering back.

BTW..you need the PS cooler tube. Don't run for long without it Either get another one from the Auto Wreckers or use a small transmission cooler.


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## 20v master (May 7, 2009)

Chickenman35 said:


> *BTW..you need the PS cooler tube. *Don't run for long without it Either get another one from the Auto Wreckers or use a small transmission cooler.


Why?


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## Chickenman35 (Jul 28, 2006)

20v master said:


> Why?


Because the PS fluid does get hot..surprisingly hot. Don't forget that it operates at pressures of 800 to 1,000 PSI when cranked hard ( Like when parking ). That creates a TON of heat.

If you Autocross or Track day it gets even hotter. The fluid will break down with heat and start to foam and varnish without proper cooling. Although Pentosin is good...it is not a full synthetic, and it will break down with too much heat.

You can never over-cool an Automatic Transmission or a PS system. The factory tube, although it looks small, works surprisingly well. It is thin wall aluminium and is placed to receive lots of air flow.


One final thought. Manufacturers don't put parts on that aren't needed. A part that isn't there, doesn't cost money to make and it will never break, thus eliminating warranty and recall costs. There's a reason why that cooling tube is there... :beer:


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## Chickenman35 (Jul 28, 2006)

Here's a couple of links on types of PS coolers and proper installation:

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

Edit: Will add more tomorrow, but I have an early work day tomorrow. Time to hit the sack.

Edit 2 : Max can probably chime in here. Anyone who Autocrosses or Track Days gets very familiar with the importance of cooling the PS pump and using top quality fluid. Inline PS filters are good too. :thumbup:


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## 20v master (May 7, 2009)

Chickenman35 said:


> Because the PS fluid does get hot..surprisingly hot. Don't forget that it operates at pressures of 800 to 1,000 PSI when cranked hard ( Like when parking ). That creates a TON of heat.
> 
> If you Autocross or Track day it gets even hotter. The fluid will break down with heat and start to foam and varnish without proper cooling. Although Pentosin is good...it is not a full synthetic, and it will break down with too much heat.
> 
> ...


The "it's there for a reason" excuse doesn't satisfy the critical thinker.  The rear ballast weight is there for a reason too, but people remove it with no ill effects, along with countless other things in the car. That said, other than the quicker ratio compared to all the other Mk4 power steering racks, there is no difference in the steering system. My Mk4 GTI has 240K miles on it, the original PS pump, rack, and lines. It has been road raced several times in high ambient temps on tight complex courses. It also has doesn't have the extra looping of the TT's steering lines that I guess is what we're calling a cooler here. I've never had a problem with the steering system. So again, why is it there? 

Do we know if the R32 has the same redundant loop? Do FWD TT's have the same lines as well? And I'm not sure where you're getting that it has a lot of airflow. It's hidden by the belly pan, aka a heat shield as far as anyone interested in an intake is concerned. :laugh:


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## Chickenman35 (Jul 28, 2006)

20v master said:


> The "it's there for a reason" excuse doesn't satisfy the critical thinker.  The rear ballast weight is there for a reason too, but people remove it with no ill effects, along with countless other things in the car. That said, other than the quicker ratio compared to all the other Mk4 power steering racks, there is no difference in the steering system. My Mk4 GTI has 240K miles on it, the original PS pump, rack, and lines. It has been road raced several times in high ambient temps on tight complex courses. It also has doesn't have the extra looping of the TT's steering lines that I guess is what we're calling a cooler here. I've never had a problem with the steering system. So again, why is it there?
> 
> Do we know if the R32 has the same redundant loop? Do FWD TT's have the same lines as well? And I'm not sure where you're getting that it has a lot of airflow. It's hidden by the belly pan, aka a heat shield as far as anyone interested in an intake is concerned. :laugh:


Lets see if I can appease the " Critical Thinker ".

I actually don't own a TT. I own an A4 Quattro ( Max invited me over from the 1.8T forum as it was getting a bit too narrow minded again ). 

I usually like to check out the different models by using ETKA, but since VAG decided some time ago to sue all of the online sites that hosted ETKA, it is getting harder and harder to check things without going to a dealer. 

First thing I wnat to check is that we are referring to the same PS Cooling tube setup.

Does the TT PS Cooling tube look similar to this?










The cooling requirements of the PS system depends on a great many variables. Weight distribution, Castor and Camber settings , Negative or Positive scrub radius and amount, width of tires and construction, front track and amount of airflow to the cooling tube, all affect the forces on the PS system and heat generated by the pump. Autocrossing is one of the hardest things on a PS pump because of the violent, large and repeated inputs. Add huge sticky tires like V710's or A6's and increased PS fluid cooling becomes a very big deal.

A lot of small lightweight cars can get away with minimal cooling. Often the cooling line is incorporated into the low pressure return line ( Although it can also go on the high pressure side ). It may be just a simple loop of tubing a couple of feet long. Generally the manufacturers put the minimum amount of cooling tube required for normal use. 

I don't own a MkIV ( and can't check ETKA anymore ), but I suspect that the PS cooling tube might be fairly short. My Audi A4 has a fairly short loop of thin wall aluminium tubing because it is placed right in front of the radiator and has excellent airflow to it. Thus my comments about air flow.

I assumed that the TT would have a similar setup. However, now that you mention that the cooling loops are located above the " Belly Pan " I can get a pretty good idea of what Audi has done. To my understanding, TT's do have a cooling issue with a small grille opening and have issues with getting enough airflow through the radiator if used for Track Days/ Autocross etc. 

So it looks like for packaging purposes, Audi has had to move the PS cooling tubes to a less than optimum location. That would explain the " Extra " coils. Less cooling air, the more coil length you need to dissipate the heat. While searching about I found several other manufactures using this approach. Usually all on high end sports cars with limited grille opening sizes.

One question about the " Belly Pan " . On my A4 Quattro, there are 3 carefully placed NACA Ducts. These direct cooling air over the engine oil pan and the gearbox. Does the TT Belly Pan use NAC ducts as well. I'm thinking that thye may have some ducting that scoops air over the cooling tubes. 

As far as the Axiom " It's there for a reason " . It still holds true...even to the " Critical Thinker " A true " Critical Thinker " would realize that we enthusiasts are an odd bunch and remove a LOT of things that we " think " makes no difference. Lets not forget hat a Manufacturer has to satisfy a gamut of EPA regulations, NHTSA regulations and build a product that satisfies a wide variety of customers from all over the world in varying climates and terrains. And some things have a better reason for being there than others :beer:

Edit: I just checked around and found that the VAG.CAT board is back up with the online ETKA catalog. For some reason, my bookmark was sending me to an old link Whoopeee!!!:thumbup:


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## Chickenman35 (Jul 28, 2006)

Lets see if this shows up:

2000Audi TT. Yes it is a complicated mess isn't it? :










1998 Audi A4 Quattro. Much simpler PS Tube setup:










2002 Golf MkIV. Looks like Cooling section is on the high pressure side...a bit unusual:


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## Marcus_Aurelius (Mar 1, 2012)

I agree, the steering system gets really hot and could use some good cooling. I don't know how well the stock loops work as I have never tested it. With 315 Hoosiers, my system leaks at the banjo bolts (even with new whashers and bolts), and at the tie rod seals. Problem seems to be heat but also pressure, since I don't have any leaks with street tires (no matter what I do).

Adam, does have a point though that there is hardly any airflow over the loop and once heated and heat soaked there is probably very limited cooling in effect without proper airflow over the tube. Maybe someone should hook up a pressure gauge to the system with/without the loop to figure out if there is any difference (the configuration with the most heat will show a higher pressure). DougLoBue drove to my house the other night to fix an exploded power steering hose, he used a silicone section on his recent reservoir relocation and it couldn't take the pressure and the heat that the system generates. We replaced it with proper high pressure hose, but it got me interested in trying a steering cooling strategy.

What do you guys think of this? I had it in the parts bin to use on my Saturn steering project but it will be helpful in the TT...opcorn:


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## Chickenman35 (Jul 28, 2006)

The fins will definitely help some.

A better choice would be a small auto trans cooler. I've used the Hayden 401 on many different vehicles used for Autocross and Track Days. Always does the trick. Note: I prefer the tube design over the stacked plate design. Stacked plate design can sometimes cause pump whine. 

http://www.summitracing.com/parts/HDA-401/


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## Chickenman35 (Jul 28, 2006)

Regarding your leaking banjo bolts. Try some Stat-O-Seals. These are for high pressure fluid applications and work great. Used on F1, Indy car and Nascar.

http://www.mpsracing.com/products/Earls/PA_Seals.asp

http://www.allsealsinc.com/statoseals.html


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## Marcus_Aurelius (Mar 1, 2012)

Chickenman35 said:


> Regarding your leaking banjo bolts. Try some Stat-O-Seals. These are for high pressure fluid applications and work great. Used on F1, Indy car and Nascar.
> 
> http://www.mpsracing.com/products/Earls/PA_Seals.asp
> 
> http://www.allsealsinc.com/statoseals.html


Thanks for the links! I am going to order some to see if it cures my banjo fitting leak on track rubber. :beer:


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## Chickenman35 (Jul 28, 2006)

Marcus_Aurelius said:


> Thanks for the links! I am going to order some to see if it cures my banjo fitting leak on track rubber. :beer:


 Added bonus. They make installing the Banjo bolts a lot easier. Bolt stays in Banjo :thumbup: 

Don't know about your TT, but on my A4 the PS Banjo bolts are a frickin' pain to install!! :banghead:


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## Redneck Truck (Jun 10, 2009)

At the risk of irrelevance, I am facing a similar issue with my TT TDI's power steering system and really want to redesign it. The pressure hose is fine - it runs from the pump, across the front, does a few loops presumably for cooling, and runs straight to the rack. The return hose, as we know, goes forward from the rack, through what I presume to be a cooling loop, back past the rack, up, down, up, down, and up to the reservoir, where it then passes down, and up again to the pump (pump is high mounted on TDI).

The TDI 4Motion down pipe I'm running rubbed through the steel (yes, it's steel, not thin-walled aluminum) pipe toward the top of one of its upward sweeps, and I lost enough fluid for the pump to air lock. I pulled the belt off and drove it home, and then yanked the return line, destroying it in the process.

Now, I seek a potentially more costly, but better solution, but I do not want to ignore all the engineering and R&D that went into making the system work as well as it does. So, here are my assumptions:

1. The return line on the Quattro/4Motion cars does the crazy loop in front because it is forced to do a similar crazy loop in back, and runs right behind the hot turbocharger. Cooling it after the rack might offset some of the heat introduced on the way to the reservoir.

2. The system is a certain volume and length both for cooling purposes and for smoothness. Additionally, there are restrictive orifices pressed into the soft hose in a few places. I had a conversation with a veteran Audi mechanic who indicated those restrictors smooth fluid flow and prevent pulsation.

3. The system is designed to dissipate heat and prevent/reduce foaming, both of which are killers to fluid when it is run through gears and pumps.

My idea is as follows:

Eliminate the line that runs behind the engine to the reservoir. Instead, tie into the soft line that runs forward from the rack to the cooler, and run that line to a small radiator (like the 2005 TT 3.2 auxiliary coolant radiator, pictured), then across the inside of the core support, directly to a reservoir mounted to the top of the pump (there is a convenient space for it).

My concerns are:

- Will such a short, simple path introduce new issues with foam and heat?
- Will substantially reducing the volume of the system create drivability issues?
- Are the internal passages of the radiator power steering fluid friendly?
- Will the system flow as well as it did, but not so well that noticeable pulsation occurs?

So below are drawings of my design. I request your thoughts and criticisms. Please try to talk me out of doing this.

CURRENT SETUP:









PROPOSED SETUP:









RADIATOR:


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## 20v master (May 7, 2009)

I like your train of thought, but don't have any info to add or answer your questions. Why on earth they decided to circle the earth, aka the engine, is beyond me.


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## Redneck Truck (Jun 10, 2009)

I suppose at very worst, it's time and money spent and lessons learned. I'll purchase the same hose I purchased to have the high pressure line rebuilt, and some good clamps, and let you guys know how it goes.


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## peter139 (May 4, 2005)

Interesting didn't know this at all


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## jbrehm (May 16, 2006)

******* Truck said:


> PROPOSED SETUP:



This is exactly what I'm going to do with mine in the Spring (I have a bunch of cooling mods to do before the Summer). And since the heat exchanger should provide sufficient cooling, I may even get ambitious and have some hoses made to delete the high-pressure side.

I'd also like to redesign the ridiculous 225TT cooling setup, but it looks like that would cost about a grand - several hundred in billet fittings (heater core, head, and block fittings), a couple hundred for a rad, and a couple more hundred for AN hardware.


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## Redneck Truck (Jun 10, 2009)

I don't know that the power steering pressure line can be improved upon, and at best, it's not hurting anything where it's at. 

A few people have expressed concerns that the radiator pictured will not be good for power steering fluid as it is made for coolant. I know oil coolers are designed totally differently, but I'm wondering just how much of a difference it will make. Any thoughts on this?

Also, the Beetle has a better return line setup, in my opinion; the return line runs forward and does a few bends in the fender/bumper area, runs up to the reservoir mounted by the battery, and shoots over to the pump. I'll be replicating this design, I suspect.


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## 20v master (May 7, 2009)

******* Truck said:


> A few people have expressed concerns that the radiator pictured will not be good for power steering fluid as it is made for coolant. I know oil coolers are designed totally differently, but I'm wondering just how much of a difference it will make. Any thoughts on this?


Think of oil viscocity versus coolant viscocity. The P/S fluid is somewhere inbetween. I'd think the volume would be so large in that exchanger that you'd want to go to a smaller oil cooler like core.


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## Chickenman35 (Jul 28, 2006)

A small automatic transmission cooler as described in post #10 is more than sufficient. Cooler mounts in front of radiator with supplied zip straps and pads. Connect to low pressure side of system. Done deal.

The Hayden 401 is the perfect size. Any other decent brand of similar size will also work. 

I would not use the auxiliary water radiator from the TT225 as you proposed. Totally wrong core design for a PS cooler. Too restrictive.


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## Redneck Truck (Jun 10, 2009)

That is disappointing, only because I was hoping to use that OEM radiator in that position. I suppose I still could, though it is probably a bit small for a water/air intercooler heat exchanger.


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## Redneck Truck (Jun 10, 2009)

Welp, I eliminated the cooler circuit altogether. Now, the return runs from the rack, across and under the radiator, up the front of the motor with the power steering supply line and the coolant overflow line, under/past the reservoir, and loops back into it before taking its normal path to the pump. Not sure how ill monitor heat during this experiment, but the system seems to work well.


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## Chickenman35 (Jul 28, 2006)

******* Truck said:


> Welp, I eliminated the cooler circuit altogether. Now, the return runs from the rack, across and under the radiator, up the front of the motor with the power steering supply line and the coolant overflow line, under/past the reservoir, and loops back into it before taking its normal path to the pump. Not sure how ill monitor heat during this experiment, but the system seems to work well.


If you find your PS fluid getting black and burnt smelling, then you'll know its overheating. But by then you could be damaging seals. Keep an eye on the fluid. Heat will break down the fluid's lubricating, anti-foaming and anti-corrosion properties. And heat can damage the seals in the rack. 

I'd still plumb in a small Auto transmission cooler in front of the engine radiator as stated before. Hydraulic Pump systems of any type always like cool, clean oil. If you autocross or track day you MUST run some sort of cooler.


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## Redneck Truck (Jun 10, 2009)

I agree, and believe me, I'm monitoring it. The good news is, the way I've routed it, adding a cooler will be a 5-minute affair.


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