Better Power Steering performace at Cold Start (weather)

[NICAT]

Hi Friends,
The car is W163 ML 2002. Steering wheel is a little hard to turn.
I previously started a thread on whether higher viscosity fluid would improve PS performance, many thought the answer was 'no'.
Today it was unusually cold outside. (No ice, no rain ) I Started the car and the Steering Wheel was shockingly very soft to turn. After driving car for 20 minutes i parked car exactly at the same place and it was hard to turn again. This is not the first time I have noticed softness on cold starts. I have experienced it many times in the past, but it was not as noticeable as now, so I just igored it.
I am currently usig ATF which has viscosity 40C- 35 mm2/s, 100C-7.6 mm2/s
PS Guy once checked pressure of pump and reported that it has reduced performace and should be replaced.
i know replacement may be an ideal solution, But if i can shift to thicker ATF and get some improvemet without having to replace pump, that would be better for me
Can you please suggest me Thicker ATF or PSF? And is it too risky to use thicker oil than OEM fluid specification in PS System ?
Regards/

 

[dippschtick]

High Temp ATF

For heavily-loaded vehicles, allowing operation at up to 70°F higher while maintain thicker viscosity than traditional ATFs

www.redlineoil.com

Red Line High Temp ATF if you want thick Dexron III.
For the record I'm not recommending it though.
Your call.

 

[NICAT]

High Temp ATF

For heavily-loaded vehicles, allowing operation at up to 70°F higher while maintain thicker viscosity than traditional ATFs

www.redlineoil.com

Red Line High Temp ATF if you want thick Dexron III.
For the record I'm not recommending it though.
Your call.

Hi. Thanks for reply.
Unfortunately US made products are not available in country
Only German, Korea and Japan

 

[bullwinkle]

I have Type A in the MGM in my sig, it’s actually helped PS performance. Not sure if it’s available overseas or not?

 

[D60]

Was this a common problem? I only ask because once Stellantis figured out aluminum wasn't great for steering boxes the problem vanished. I had very similar symptoms.

But I can't believe your application is recirculating ball so VERY different methods to achieve steering/assist.

 

[joegreen]

Maybe try some seafoam transtune in the power steering and see if it helps.

 

[Plawan]

Does your power steering system leak fluid? Could be that the higher viscosity when cold accommodates/helps prevent loss of pressure do to a bad seal or seals.

 

[userfriendly]

For power steering, I like high vis ATFs or a THF that meets JD 20D & C. Also ISO 46 AW hyd and synthetic compressor fluids.

 

[michael007]

Hi. Thanks for reply.
Unfortunately US made products are not available in country
Only German, Korea and Japan

In the future, syrush.com is a great forwarding service I use to get US products abroad.

$1 receiving fee + USPS rates to your country

Shows it's under $50 to send 4lbs to Azerbaijan which is enough for a few bottles

 

[NICAT]

No leak from power steering,
Unfortunately at customs there is issue with liquids as they can be flammable, explosive or etc.
From other thread i found this

Originally Posted by RyanY
This one. Yes, the viscosity does not exactly match Honda but it works well. I can't say it's the best but I like it better than the Honda fluid. [/img]

There are two Honda fluids with two different viscosities, an 11.5 cSt viscosity (older) and one with 6.5 cst viscosity (later).

What technical information do you have to show that it is better than Honda fluids?

There are PSF fluids available for Honda in the country, but i can not find their viscosity numbers at websites or on the bottles. Can you help me which bottle (or OEM Number) has viscosity of 11.5cst ?

 

[Egg_Head]

I would be very hesitant to introduce a different fluid. Have you tried flushing the current fluid and replacing with Pentosin CHF 11S, which is what MB recommends or an equivalent? Also the PS reservoir contains a built in filter. You need to replace the entire reservoir to replace the filter but it is a relatively easy job. Get the Lemforder reservoir and don't forget to replace the gasket.

Mercedes Power Steering Reservoir Replacement Kit - Lemforder 0004602583

Mercedes Power Steering Reservoir Replacement Kit - Lemforder 0004602583

www.fcpeuro.com

 

[KrisZ]

Mix some motor oil with the ATF to thicken it up. Hydraulic systems are simple things and don’t need specialized lubricants.

 

[eljefino]

I think you have an internal problem, like a sticking relief valve.

 

[Mcbeem5]

This works good in subzero temperatures---

ACDelco GM Original Equipment 10-5044 Cold Climate Power Steering Fluid - 32 oz​

• Minimizes pump squeal for quieter ride
• Low temperature fluidity to improve power steering response in cold weather

 

[JHZR2]

Did the manual actually specify atf for that vehicle? If it actually specified one of the Pentosin hydraulic fluids, you may have seals issues now.

 

[NICAT]

Hi. Thanks all for answers.
No Leak at this point
Manual specifies Pentosin CHF 11

Mix some motor oil with the ATF to thicken it up. Hydraulic systems are simple things and don’t need specialized lubricants.

This is very attractive suggestion Wouldn't Engine oil be bad for Seals and cause leak ? Should i use mineral or synthetic oil ?

 

[KrisZ]

This is very attractive suggestion Wouldn't Engine oil be bad for Seals and cause leak ? Should i use mineral or synthetic oil ?

Both are petroleum based, I don't see how engine oil could possibly harm seals. Maybe if you used a high mileage oil with seal swellers, perhaps.

 

[SHOZ]

My Genesis Coupe came with Pentosin CHF 202 supposedly due to cold weather issues.

 

[NICAT]

Both are petroleum based, I don't see how engine oil could possibly harm seals. Maybe if you used a high mileage oil with seal swellers, perhaps.

That is great. i think to reduce the amount of Engine oil required for the optimum viscosity i should be usig highest viscosity available right ? like 10w-60.

 

[KrisZ]

That is great. i think to reduce the amount of Engine oil required for the optimum viscosity i should be usig highest viscosity available right ? like 10w-60.

Well, I would not expect any miracles here because a cold oil is several times more viscous than when it is up to the operating temperature. You may get a little bit of improvement, but I would not expect much.
If your pump is worn out, it will need to be replaced eventually.

I would probably try cleaning it first. Maybe use an engine flush in it and see what happens. After that I would try to use something thicker, but I would start budgeting for a pump replacement. Maybe find a place that rebuilds them? In America we are a throw away society and hardly anything gets truly repaired here, but your place might be better in this regard.