Chrysler 300m -> do you really need a power-steering fluid cooler?

Only on the skid-pad slalom...however, I did once see a TSB, on a Chrysler, in fact (Grand Caravan??) ...that had ADDING just such a pipe to the PS system to cure a perceived noise problem/complaint from customers.

That doesn't mean your car would make noise without it, but it does lead rise to the question of whether it just /cools/ the fluid or somehow also helps the system by increasing the travel-path and volume of fluid inside.

GW (insert week-long useless argument over fluid dynamics here....lol)

Not having seen your cooler and the leaking spot my suggestion might not work but it most likely could easily be fixed by simply putting a piece of rubber over the hole and a hose clamp over that. Or cut out a 6" length where the damage is and put an appropriate sized piece of hydraulic hose in the gap secured with hose clamps.

Take it to a competent welder and have them weld the hole closed. Flush the pipe and reinstall.

Or removing the cooler and soldering the hole shut, either by just filling it with solder, or soldering a piece of thin sheet over top of the damaged section.

nate

I would have to cut the pipe (where the hole is) to be able to put a short length of hose over the hole because the brackets are welded to the pipe and I can't just slide a piece of hose down to where the hole is.

I like this idea because this cooler-pipe is on the low pressure side (PS-fluid flows from this pipe into the reservoir).

Local chrysler dealer wants about $120 for this pipe (P/N 4782260AD). There apparently is something called a "cooler kit" (P/N 5010360ac) that the dealer wants $370 for - he can't tell me just what this kit has that makes it so expensive. It could be an actual radiator (pipe with fins).

This is an aluminum pipe. I can't solder aluminum - can you?

The hose clamp idea won't likely work... maybe if it is on the return side but still likely no. When I kludged a leaking PS line on a beater because it was too difficult to replace but the damaged area was accessible I used brake line as close to the diameter of the PS tube as possible (3/8" brake line for a 10mm PS tube) and brake fittings flaring the tubes so it all connected together. This held just fine.

However, I notice it is Al. I don't think brake line flares will form correctly for Al tube. May require an appropiate flaring tool and fittings for the material.

But looking at that part, I doubt it is worth the trouble over buying a new one or just going the self serve salavage yard.

Yep, it's a small finned unit like the oil cooler. Hose will work. So would simply bending up a new one using steel brake line (done a bunch on different vehicles)and mounting it with nylon tube clamps.

As a matter of fact, yes I can. So can most radiator and refrigeration shops. You could as well IF you have a good torch and the proper rod.

You're saying that even if the cooler is on the low-pressure (return) side, bridging the leak with a hose would likely not work?

From the factory service manual:

---------------------- POWER STEERING FLUID COOLER

DESCRIPTION

All models of this vehicle are equipped with a cooler for the power steering system fluid (Fig. 1). The power steering fluid cooler is located at the front of the vehicle. It is mounted to the radiator lower support just forward of the air-conditioning condenser and just rearward of the front fascia (Fig. 1). The cooler is positioned so it is in the air flow through the front fascia of the vehicle.

OPERATION

The purpose of the cooler is to keep the temperature of the power steering system fluid from rising to a level that would affect the performance of the power steering system.

The cooler used on this vehicle is referred to as a fluid-to-air type cooler. This means that the air flow across the tubes of the cooler is used to extract the heat from the cooler which it has absorbed from the power steering fluid flowing through it. The cooler is placed in series with the power steering fluid return line, between the steering gear and the power steering fluid reservoir. This lowers the temperature of the power steering fluid prior to it entering the power steering fluid reservoir where it is resupplied to the power steering pump.

----------------------

The two hoses connected to this aluminum cooler/pipe are 3/8" ID and are secured using ordinary spring clamps (not screw clamps). Clearly we are not talking about high pressure. The pipe is either painted or anodized with a black coating, and is expanded to about 5/8" OD for it's entire length except for the inlet and outlet, which is reduced in size to accomodate the inlet and outlet hoses.

So I plan on cutting this aluminum pipe where it was worn through so I can insert a short length of hose to effectively repair the leak. The only hose that I was able to easily buy locally was 1/2" heater hose that with some effort will stretch over the 5/8" pipe. This hose only needs to be 2" long.

I've been replacing the leaking power steering fluid with ATF+4 transmission fluid (because I've found some TSB's that say it's ok to do that) - but I don't know how compatible heater-hose is with transmission fluid. Anyone know?

Sorry - I'm not paying $120 for a 4-ft long piece of aluminum pipe.

The car I dealt with rusted PS lines on didn't take to such repairs on either side of the system.

If you already know how to fix it, then fix it. Or this some stupid test of how well people on usenet know each particular make model and year?

If it's held with hoses and spring clamps from the factory then it might work. But keep in mind you have no flare on your tube ends to retain the clamp or make for a good seal. You're relying entirely on the compression of the clamp to do both jobs. Maybe that's enough maybe it's not. Sometimes you're talking non-trivial pressure sometimes practically nothing on the return side. Return hoses are spec'd at 250psi working pressure, so the possible range is probably something like 0 to

Found some references to back up the above:

I don't know what he's saying, but I'll say that if the tube is leaking in one place, and you seal it up there, it will probably start leaking someplace else.

--scott

If I remember the OP correctly, he determined that it was leaking from having been bent and one spot abrading against a bracket or piece of bodywork - not a failure due to corrosion or fatigue cracking. So bending it back and fixing the leak might work for a good while.

I would definitely use something like trans cooler hose and "high pressure" type screw and nut clamps, not low pressure fuel line and worm drive clamps if attempting a band-aid fix.

However, by the time one gets all that stuff together, the cost of the proper materials might approach the cost of a used cooler from a recycling yard... Likewise for soldering and/or welding, if one does not already have the tools to do it oneself.

nate