msp177

Does anybody have any information on an ML320 Power Steering Leak? How to repair? Where the leaks come from? Resevoir is going down below the dipstick level after about a month, so it is a slow leak. At this point then it starts to whine. Any help is greatly appreciated.

mihir_d

Power steering reservoir O-rings are susceptible to drying, hardening & leaking after around 5-8 years depending on where you live.

It's a cheap $130 fix to replace the reservoir. Actually just replacing the O-rings works too, but the reservoir itself is around $70 so might as well replace the whole thing.

If it's not the reservoir, then it's the pump, which is far more expensive to replace....

mihir_d

So it is 8 years or more of age. It is very likely the reservoir O-rings. Replace the reservoir & see if the leak stops.

msp177

Thanks for the help. Do you happen to have the procedure? Do you have to bleed the system after the o ring and/or resevoir replacment? Again, do you have procedures on this?

Thanks in advance for the help!

mihir_d

I would advice going to the dealer/mechanic that has a lift - they charged me $55 labor (half an hour) & $70 in parts - it is that cheap..

The thing that the dealer can do which you cannot easily is lift up the truck after doing the repair, wipe all the leaked fluid trails and use a flash light to verify that there are no other leak points..

In my opinion, that check the mechanic did after refilling the power steering circuit was priceless...

springerfever

You might check with the dealer and see if there was a recall accomplished on your ML. Its been a while but, I think it was in 2001/02/03 or thereabouts. Also there is a screen in the reservoir that needs replacing occasionally.

Lastly, I found a product that I used many years ago to stop a slow but incessant leak with my ps pump. Its made by Valvoline and called MaxLife Power Steering Pump Fluid. Its compatable with MB PS fluid and helps to recondition seals and gaskets. It fixed my problem and my ML has the original pump and 295,000 miles on it ! Might want to give it a try........

I check my PS reservoir about every six months or so and always top off with this fluid. As with brake fluid, make sure to thoroughly clean around the cap, avoid getting any debris in the reservoir and keep the cap tight.

mihir_d

I should think about switching to that kind of ps fluiid to prolong the life of my ps pump. I am at $145k miles - 150k miles might be a good milestone to replace the fluid to something like what you suggested...the truck is getting all it's fluids flushed at 150k miles anyways...

Do such fluids exist for the brake & coolant liquids as well?

By the way, as a tip to people driving the ML to extended miles, I also started dumping chevron Techron concentrate additive to my gas tank every 3000 miles off late - is supposed to help the fuel injectors in the long run...

mihir_d

Hit 160k miles yesterday.

Mechanic has diagnosed a very small leak coming from the rack seal (2-3 drops overnight).

I am going to try that Valvoline product that springerfever has suggested.

Mechanic suggests not to worry so much about such a small leak until it gets worse.

Rack is a $2000 fix...he thinks, it's not worth putting that much money in a 11 year old vehicle...

maliboo402

mihir, Did the valvoline product work?

mihir_d

So, I am at 168K miles...

I talked to my experienced mechanic before starting the Valvoline therapy for the rack :-) and he said, anything that aggressively works on the seals is not good, because, if the seals over expand, that could introduce more leaks.

So, to be on the safer side, instead of emptying the PS fluid and replacing it entirely with Valvoline, I started adding Valvoline as a refill for the 1-2 drops/day that the rack is leaking..

I add probably adding half an ounce every 2-3 weeks...

Its been 2 months, since I am doing this and it appears the leak is slowing down...

This product is known to work and is certainly not going to harm your PS circuit...so will not hurt in trying it...I am expecting the leak to disappear over 6 months to 1 year time frame..

Mine is only losing 1 or 2 drops a day, so it really isn't that bad to start with.

MercMuzz

hey mihir......I have the same leak.....how is the leak going since your last post....

mihir_d

The leak has slowed down for sure...maybe completely gone now. There is no more 1-2 drop overnight dripping. Maybe rack is still a bit moist...it should all go away in 2-3 months, I guess...

Power steering rack seepage is normal on aging cars....you just gotta learn to live with it.....

MercMuzz

hey guys, had a power steer leak coming from the rack where the high and low pressure hoses join the rack. I have had the power steering resevior recall performed so I knew it wasn't that.

I thought i would check the tension of the torx bolts before I went and got any further advice. You wouldn't believe it, the top bolt was very loose. I simply used a 15mm socket and ratchet to tighten it up and no more leaks......Hope this helps someone....

Muzz

mihir_d

My bolts were checked by a mechanic & retightened.

My car is now 12 years old. The seals are going to start seeping. My leak is so little to begin with, it has never really bothered me. sometimes just 1 drop overnight.

Giving the seals a mild treatment of sealing power steering fluid like that Valvoline product is the best thing to do for me...

mihir_d

Last 2 months, no drop in PS fluid level. Might have something to do with warming of season temperatures as well.

Erwin8r

Sorry to revive this necro-thread, but I'd also like to report success with a simple tightening of one of the bolts connecting the power steering lines to the steering rack. After having an "independent" shop quote me $250 for a high-pressure line + labor charges, I decided to have a look myself (after reading the above posts). Sure enough, one bolt was almost finger-tight... My ML is an '02, so the bolts are a bit easier to get at than the older models...

Tightened it up, bled as per the procedures outlined (fill, lift front, truck off, turn wheels back and forth 30 times, then re-fill reservoir), and took out for a test drive. No more leaks!

On another not so successful note, I couldn't get my new reservoir on--I couldn't push it in far enough to get the spring clip back. I gave up and re-installed the old one (it wasn't damaged or leaking anyway...). I might give the new one a shot again at some point.