Technical Steering pump issue? Or steering fluid?

[Rafao95]

So last year I replaced my original rack with a rebuilt one.
The original rack was not leaking, except that the pinion that connects to the steering shaft had a little clearance, so on rough roads I could feel my steering wheel and steering shaft shaking.

The rebuilt rack had no clearances and nothing wobbled on rough roads. However, the rack was very tight and when cornering, my steering wheel wouldn't go to the center. Also, when parking, moving the steering wheel from lock to lock quickly, I could hear some noises coming from the rack (I was told that rebuilt racks use very hard rubber seals, which is why the rack was very hard and made noises due to the internal pressure in seals). I also unadjusted the preload screw a little, but no success.

So I replaced the rack again with a used one, but in excellent condition. No noise when turning the wheel quickly and no clearance in the pinion. It was excellent until a few weeks later, I can feel the steering wheel getting a little heavy when the car is hot.
When cold it's good, but when hot it starts to get a little heavy. Also, when stopped with the engine running, at idle, when I start to move the steering wheel, I hear the steering pump making whining noise. If I force full lock, I can hear a loud sound, but I think this loud noise is normal in all cars with full lock.

So, my concern is about the groaning/whining noise when turning the steering wheel slowly when the car is stopped and the steering is a little hard.
I don't know what kind of fluid my mechanic filled, but the color is the same (red). If I change the fluid to the correct one (assuming it's not the correct one my mechanic filled), will that solve the problem? Or do I need to change the steering pump too? My mechanic and I don't have the gas pressure tools to measure the steering pump pressure.
The fluid is at the correct level and is not bubbling.

If the steering is good when it's cold, could it be the steering fluid?
How can I diagnose without spending a lot of money? (change the fluid first and if it doesn't work, change the pump and buy more fluid)

 

[bugsymike]

I couldn't find your vehicle specifically, but other Fiat of that era seem to use Dexron 2 power steering fluid, although not sure if changing oil will cure the issue. Perhaps others can advise? I know certain makes of vehicle like older Citroens could be damaged if wrong fluid used, I think they used LHM mineral fluid but there are many different types now on newer vehicles.
Re the poor rebuilt steering rack, I have experienced similar from so called "specialists" and would be sceptical about "hard rubber seals" being the cause on the rebuilt one. Did they "Recon" your old unit, as they may have simply removed shims to take out the slack, then painted it up pretty and charged a good price!!! That would account for not "self centreing"
As you say when held on full lock the pump pressure relief valve can be noisy normally, if held there for too long it overheats the oil.
Any chance of a blockage/restriction, is there a good steady return flow to the reservoir?
Does the power steering fluid get hot quickly, if the oil overheats it can smell like burnt chip oil and gets darker in colour?
With engine off and car in the air does steering feel good when going lock to lock?
When steering pump makes noise when not on full lock, can you use a "listening stick" to hear if the bearings are noisy in the pump?
Normally if drive belt is the problem slipping etc. it is worse when cold and sometimes visible when looking at the belts and pulleys running.
I have seen belts slipping when new and correctly adjusted due to a previous slipping belt "polishing" the pulleys
Re the original "self centering" issue after changing the steering rack wheel correct wheel alignment is critical.
Unrelated I know, but I have had cars that biased to one side, but when safe to do so I ran the car in neutral with ignition on but engine off down hill and it steered correctly so the fault was in the power steering rack in that case.

 

[Rafao95]

I couldn't find your vehicle specifically, but other Fiat of that era seem to use Dexron 2 power steering fluid, although not sure if changing oil will cure the issue. Perhaps others can advise? I know certain makes of vehicle like older Citroens could be damaged if wrong fluid used, I think they used LHM mineral fluid but there are many different types now on newer vehicles.
Re the poor rebuilt steering rack, I have experienced similar from so called "specialists" and would be sceptical about "hard rubber seals" being the cause on the rebuilt one. Did they "Recon" your old unit, as they may have simply removed shims to take out the slack, then painted it up pretty and charged a good price!!! That would account for not "self centreing"
As you say when held on full lock the pump pressure relief valve can be noisy normally, if held there for too long it overheats the oil.
Any chance of a blockage/restriction, is there a good steady return flow to the reservoir?
Does the power steering fluid get hot quickly, if the oil overheats it can smell like burnt chip oil and gets darker in colour?
With engine off and car in the air does steering feel good when going lock to lock?
When steering pump makes noise when not on full lock, can you use a "listening stick" to hear if the bearings are noisy in the pump?
Normally if drive belt is the problem slipping etc. it is worse when cold and sometimes visible when looking at the belts and pulleys running.
I have seen belts slipping when new and correctly adjusted due to a previous slipping belt "polishing" the pulleys
Re the original "self centering" issue after changing the steering rack wheel correct wheel alignment is critical.
Unrelated I know, but I have had cars that biased to one side, but when safe to do so I ran the car in neutral with ignition on but engine off down hill and it steered correctly so the fault was in the power steering rack in that case.

Thanks for your reply.

About the alignment, I did it after replacing all the steering racks. The car runs straight with both racks (original, rebuilt and the last one), so I believe the steering rack is not a problem.

Unfortunately, I gave away the original rack to get a "discount" on the rebuilt one. Worst mistake I ever made. There are no more rebuilt parts for me, I prefer to use used parts but in excellent condition, unless there are no more used parts.

Regarding the steering fluid, the temperature is normal as before. The fluid is clear red and does not darken (it was a little dark when I used the rebuilt steering rack, but on this last one, it is a perfect clear red). And it does not smell like burning. My only concern is the steering pump, as it makes a high whining noise when turning the steering wheel smoothly to either side. I don't see any blockage, at least. How can I be sure about this?
With the engine off and the car in the air, I think (but it could be my imagination) that the steering wheel is a little stiffer than with the original rack, but I am not sure. Also, the tire rod ends are new, which may be why it feels a little stiffer.

 

[bugsymike]

Thanks for your reply.

About the alignment, I did it after replacing all the steering racks. The car runs straight with both racks (original, rebuilt and the last one), so I believe the steering rack is not a problem.

Unfortunately, I gave away the original rack to get a "discount" on the rebuilt one. Worst mistake I ever made. There are no more rebuilt parts for me, I prefer to use used parts but in excellent condition, unless there are no more used parts.

Regarding the steering fluid, the temperature is normal as before. The fluid is clear red and does not darken (it was a little dark when I used the rebuilt steering rack, but on this last one, it is a perfect clear red). And it does not smell like burning. My only concern is the steering pump, as it makes a high whining noise when turning the steering wheel smoothly to either side. I don't see any blockage, at least. How can I be sure about this?
With the engine off and the car in the air, I think (but it could be my imagination) that the steering wheel is a little stiffer than with the original rack, but I am not sure. Also, the tire rod ends are new, which may be why it feels a little stiffer.

Generally power steering pumps are only noisy when held at full lock, is it possible to compare the noise from pump on a friends vehicle when idling and revving stationary, even though a different make, as long as it isn't an electric power steering.
Did you try using a long screwdriver or similar as a "listening stick" against the pump?

 

[tjr]

Hmm, +1 here... Noisy pump when having to work. I was hoping it would just be changing the fan belt.
The instruction book (in German) for this earlier 1995 Fiat barchetta states 1 liter Tutela GI/A for Hydraulische Servolenkung (Power Steering).

 

[bugsymike]

Hmm, +1 here... Noisy pump when having to work. I was hoping it would just be changing the fan belt.
The instruction book (in German) for this earlier 1995 Fiat barchetta states 1 liter Tutela GI/A for Hydraulische Servolenkung (Power Steering).

Regarding the belt, often old belts get noisy and hard.
To prove the noise is coming from there, you can direct a spray of WD40 or similar just at the belt, if noise goes away then you have found it. The WD40 is thin and will soon rub off so don't worry about contamination form that. In the old days dodgy car salesmen when they had a noisy fan belt used to rub a childs crayon on it to make the noise disappear
Tutela is just Fiats version, if you look up the specification of Dexron 2 you should find it exceeds the specification of the Tutela version.
This is copied from a previous Fiat Forum piece. :-

Lazac​

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JoinedJun 28, 2018Messages20Points9

• Dec 26, 2018
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• #1

Hi,

Can I use Tutela GI/E which is dexron III, instead of Tutela GI/A, which is Dexron II in the power steering system?

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KungFooPanda​

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JoinedDec 17, 2018Messages199Points128

• Dec 26, 2018
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As far as I know it’s backward comparable. I used Dexron III in my GT4 when it should have had Dexron II in it. No issues at all. The only time you have to be careful is when you’ve got something like a Honda! Then you have to use there power steering and axle fluids as they are the only supplier. I found this out to my expense! having changed the fluid (That Millers oils suggested) I then had to take it all out again. Thankfully, the Honda stuff was a clear liquid and the other was a red...

 

[tjr]

Regarding the belt, often old belts get noisy and hard.
To prove the noise is coming from there, you can direct a spray of WD40 or similar just at the belt, if noise goes away then you have found it. The WD40 is thin and will soon rub off so don't worry about contamination form that. In the old days dodgy car salesmen when they had a noisy fan belt used to rub a childs crayon on it to make the noise disappear

Thanks @bugsymike, just wishful thinking I suppose. The steering is turning heavy, the pump noisy, and the fluid is turning dark..

Will check with new fluid, the WD40 trick and for steady return flow before going after the pump.

If(!) I interpret ePER correctly the pump 46763559 fits both the M1 and 2(?). What wears on a pump, ie would it make sense to open it up and change the gaskets?
Anyone vouch for mounting a hydraulic fluid filter?

Thanks,
tjr

 

[bugsymike]

Thanks @bugsymike, just wishful thinking I suppose. The steering is turning heavy, the pump noisy, and the fluid is turning dark..

Will check with new fluid, the WD40 trick and for steady return flow before going after the pump.

If(!) I interpret ePER correctly the pump 46763559 fits both the M1 and 2(?). What wears on a pump, ie would it make sense to open it up and change the gaskets?
Anyone vouch for mounting a hydraulic fluid filter?

Thanks,
tjr

I think it would be more the bearings and pump vanes rather than gaskets, especially if a old dirty rack has been circulating fluid through it. I have never seen a filter on a vehicle PAS system.
If you get a long screwdriver against your ear and carefully on the pump when running it should help locate the noise, just keep away from moving parts.

 

[Rafao95]

Sorry for my late reply.

I just got the Tutela GI/A and I will try to change the steering fluid on Sunday, if possible (lack of time).
The noise only happens when turning the steering wheel. When I don't touch the steering wheel there is no noise, so I think the noise comes from the steering pump and not the belt (I asked a friend to turn the steering wheel when looking at the steering pump and the noise comes from it, but I will try with a long screwdriver touching on the steering like you said as a "listening stick").
Although the belt is 9 years old, it will be changed this month (100 thousand km maintenance). But I don't think the belt is slipping on the steering pump.

Also, if I accelerate when parked, I don't notice any change on steering feel.

For the pump to be damaged, the fluid would have to be dark, right? Could the darkness be the filings from the propeller blades? Or how does a pump go bad if the fluid is still clear?
If the pump is always running, and only makes noise when turning, it is impossible to be in the bearings, otherwise the pump would always be making a groaning noise.

 

[bugsymike]

Sorry for my late reply.

I just got the Tutela GI/A and I will try to change the steering fluid on Sunday, if possible (lack of time).
The noise only happens when turning the steering wheel. When I don't touch the steering wheel there is no noise, so I think the noise comes from the steering pump and not the belt (I asked a friend to turn the steering wheel when looking at the steering pump and the noise comes from it, but I will try with a long screwdriver touching on the steering like you said as a "listening stick").
Although the belt is 9 years old, it will be changed this month (100 thousand km maintenance). But I don't think the belt is slipping on the steering pump.

Also, if I accelerate when parked, I don't notice any change on steering feel.

For the pump to be damaged, the fluid would have to be dark, right? Could the darkness be the filings from the propeller blades? Or how does a pump go bad if the fluid is still clear?
If the pump is always running, and only makes noise when turning, it is impossible to be in the bearings, otherwise the pump would always be making a groaning noise.

Normally the pas belt if faulty only make the noise when you turn the steering as it puts more load on the belt, much in the same way if you turn on headlights.
Also if damp morning old belts may squeal.
The oil changes colour if prolonged overheating due to load etc. so may not show up for some time. It is the heat that changes the colour more than particles muck etc.