Replaced power steering pump...

[Algypan]

Ok, so last week I replaced the high pressure power steering hose on my 2004 T5 1.9. after swapping the hose and topping up and bleeding the system it was making some weird noises still while turning.

Anyway I finished work and all of a sudden the steering was heavy, like trying to steer with the engine off. At this point I figured I had somehow damaged the new pump which I only put on last year...

So skip ahead to today, new pump, same one as previously fitted arrives and I've been out fitting it, topping up and bleeding it. However now the fluid seems to be smoking after a couple of minutes, the steering is still just as heavy. I felt the power steering pipe under the van while it was running at it was very hot. Not sure what else I can do or what I've done.

The pump and rack were replaced last year at the same time so I know the rack is ok. Could I still need to bleed it more??

Thanks

 

[DXX]

Ok, so last week I replaced the high pressure power steering hose on my 2004 T5 1.9. after swapping the hose and topping up and bleeding the system it was making some weird noises still while turning.

Anyway I finished work and all of a sudden the steering was heavy, like trying to steer with the engine off. At this point I figured I had somehow damaged the new pump which I only put on last year...

So skip ahead to today, new pump, same one as previously fitted arrives and I've been out fitting it, topping up and bleeding it. However now the fluid seems to be smoking after a couple of minutes, the steering is still just as heavy. I felt the power steering pipe under the van while it was running at it was very hot. Not sure what else I can do or what I've done.

The pump and rack were replaced last year at the same time so I know the rack is ok. Could I still need to bleed it more??

Thanks

If the original pump was damaged I would think the fluid is also contaminated, you don’t mention renewing the fluid before fitting the new pump?
They are vane pumps which are easily damaged by contamination, it’s a good idea to routinely renew the fluid by removing the return hose on the reservoir and extending it to a container to catch the returning fluid while somebody steers and you top up the reservoir with new fluid.
There is a pressure relief valve on the pump, if this is leaking due to contamination it will throttle the oil and it will get very hot, it will also be very noisy.
Smoke as you mention or maybe vapour would almost certainly be caused by the pump running dry, if it has that pump is toast and will have deposited more debris.
There’s a strainer in the bottom of the reservoir, if you syringe the reservoir out you will be able to check for debris, note that is just a strainer and not a filter so it won’t catch everything. Some people install a filter in the return, I’m not convinced that’s a good idea as a permanent installation as they don’t have a by-pass function if they are clogged.
If you do have debris in the strainer it’s safe to say that the system is contaminated and needs flushing out, preferably not with a PAS pump as that will damage the pump.
Are you sure that the hose fabricator used hose that is compatible with PAS fluid, some hydraulic fluids can dissolve certain rubbers in a very short time?

 

[Algypan]

If the original pump was damaged I would think the fluid is also contaminated, you don’t mention renewing the fluid before fitting the new pump?
They are vane pumps which are easily damaged by contamination, it’s a good idea to routinely renew the fluid by removing the return hose on the reservoir and extending it to a container to catch the returning fluid while somebody steers and you top up the reservoir with new fluid.
There is a pressure relief valve on the pump, if this is leaking due to contamination it will throttle the oil and it will get very hot, it will also be very noisy.
Smoke as you mention or maybe vapour would almost certainly be caused by the pump running dry, if it has that pump is toast and will have deposited more debris.
There’s a strainer in the bottom of the reservoir, if you syringe the reservoir out you will be able to check for debris, note that is just a strainer and not a filter so it won’t catch everything. Some people install a filter in the return, I’m not convinced that’s a good idea as a permanent installation as they don’t have a by-pass function if they are clogged.
If you do have debris in the strainer it’s safe to say that the system is contaminated and needs flushing out, preferably not with a PAS pump as that will damage the pump.
Are you sure that the hose fabricator used hose that is compatible with PAS fluid, some hydraulic fluids can dissolve certain rubbers in a very short time?

I looked at the strainer after I emptied the fluid out of the reserviour before removing the old pump and it looked clean. I also currently have one of the in-line magnetic filters that I fitted from last time I did the pump and rack as a recommendation.

I couldn't quite get both the wheels off the ground when bleeding but it didn't have the full weight on them. This is due to the size of my jack and my driveway is super skinny that I don't actually have room the safely jack up both sides. Could this be part of the problem? If I remember last time, I didn't bleed it with the wheels off the ground anyway.

Thanks for your help.

 

[DXX]

The only reason to jack it off the ground is to reduce the load, as long as it’s going full lock it should bleed through providing there are no blockages, the pump isn’t damaged and the pressure relief valve isn’t wide open. I’m not sure what the pump vanes are made of but it’s not going to be steel, they will almost certainly be plastic so a magnet isn’t going to attract much pump debris.
Are you sure the inline filter isn’t causing a restriction?

 

[Algypan]

The only reason to jack it off the ground is to reduce the load, as long as it’s going full lock it should bleed through providing there are no blockages, the pump isn’t damaged and the pressure relief valve isn’t wide open. I’m not sure what the pump vanes are made of but it’s not going to be steel, they will almost certainly be plastic so a magnet isn’t going to attract much pump debris.
Are you sure the inline filter isn’t causing a restriction?

I wouldn't even know how to find out if it was restricted to be honest, I mean, I can take it off but I wouldn't know what I was looking for. I'm almost certain I fitted the filter before topping up and bleeding the system last time the pump was replaced.

Unsure where to go from here...

 

[DXX]

I assume the filter is on the return line to the reservoir and not the suction?
Is the fluid returning to the reservoir at a steady rate, constant flow?
Have you tried removing the additional inline filter?

 

[Algypan]

I assume the filter is on the return line to the reservoir and not the suction?
Is the fluid returning to the reservoir at a steady rate, constant flow?
Have you tried removing the additional inline filter?

I did think about taking it off but I had to cut a chunk of the pipe off as it was too long just splicing the filter in, but now it wont reach to the reserviour without it. I've ordered a new filter to pick up Monday.

Filter is on return line. I can't say I've noticed it flowing back into reserviour though... is that only something I can see by having someone else steer?

 

[Algypan]

So I've looked at it again just now, started it up and the steering felt normal, so I proceeded to do lock to lock again and after around 3 minutes I noticed the steering fluid was slowly rising in the reserviour and as it got higher (about an inch from the top) the steering started to get slightly heavy again and the fluid was starting to steam/ smoke. I turned it off and felt all the power steering pipes and they were quite warm, probably too warm for 3-5 min run.

 

[DXX]

I couldn't quite get both the wheels off the ground when bleeding but it didn't have the full weight on them.

You could just take the wheel off where needed, this would reduce the load on the pump while you bleed it through.
I can only think of two sources of the heat you describe;
1. Damaged pump.
2. Pressure relief valve on the pump throttling (stuck open).

 

[Algypan]

You could just take the wheel off where needed, this would reduce the load on the pump while you bleed it through.
I can only think of two sources of the heat you describe;
1. Damaged pump.
2. Pressure relief valve on the pump throttling (stuck open).

Do you think I could of received a faulty pump then or would this have been my fault potentially? I did prime it before installation and didn't let the reserviour run empty, so it shouldn't have ran dry at any point. I guess I could take it off and push the pin for the release valve to see if it moves freely or not to rule that out?

The pump was a FEBI bilstein if that makes any difference. I thought it was a decent brand but maybe I'm wrong. Would be interesting to see if anyone else has had issues with a FEBI pump.

 

[DXX]

Do you think I could of received a faulty pump then or would this have been my fault potentially? I did prime it before installation and didn't let the reserviour run empty, so it shouldn't have ran dry at any point. I guess I could take it off and push the pin for the release valve to see if it moves freely or not to rule that out?

The pump was a FEBI bilstein if that makes any difference. I thought it was a decent brand but maybe I'm wrong. Would be interesting to see if anyone else has had issues with a FEBI pump.

There shouldn’t be any issue with a Febi pump reliability. I think you need to eliminate the non standard return filter as a cause. If the hose is now too short as you say you could just run it to a container for a few seconds to prove whether there is return flow without the filter.

 

[Algypan]

There shouldn’t be any issue with a Febi pump reliability. I think you need to eliminate the non standard return filter as a cause. If the hose is now too short as you say you could just run it to a container for a few seconds to prove whether there is return flow without the filter.

What I don't understand though is the filter wasn't an issue before when the steering system was replaced, why would it all of a sudden be a problem now?

Thanks

 

[DXX]

What I don't understand though is the filter wasn't an issue before when the steering system was replaced, why would it all of a sudden be a problem now?

Thanks

Possibly it’s done what it was installed to do and now it’s blocked? Hence no flow.

 

[Algypan]

Possibly it’s done what it was installed to do and now it’s blocked? Hence no flow.

I've ordered a replacement original hose for that section, so I'll pop that on and try again and report back

 

[JOG]

@DXX drawing on his extensive engineering experience to remotely diagnose issues for a forum member. Wonderful to see.

 

[Algypan]

@DXX Ok, so today I put a new reservoir and hose on, I disconnected the hose from the bottom of the reservoir into a container and turned the engine on to let it flush through the fluid. I only had 1 and a half liters with me so I've had to stop (leaving the reservoir half full) and wait until I can pick some up tomorrow to continue the flush.

It was almost jet black! I thought maybe after a liter it would start to run clearer, seeing as it was all fresh fluid only last year. I'm going to pick up another 3 liters tomorrow and run that through that to see what happens.

Also, I'm not sure if I'm flushing it properly. Currently I'm getting my 9 year old daughter to fire up the engine and I'm just topping up the reservoir and keeping an eye on the container filling up. I thought maybe I would need to turn lock to lock also but the fluid runs through very fast.

On as side note... I no longer have a weep from that hose anymore now that it's new.

 

[DXX]

From post #2 I queried, note that the new hose should have the specification marked at intervals on the outside of the hose.

Are you sure that the hose fabricator used hose that is compatible with PAS fluid, some hydraulic fluids can dissolve certain rubbers in a very short time?

Not surprising it’s black as you reported earlier that it was overheating, question is why and what’s happened as a result.
Do you have a return flow now.
To flush the system you need to divert the oil from the return to a container and top up the reservoir and definitely not allowing the reservoir to run dry.
It sounds to me like you have disconnected the suction hose instead? I hope not or the pump will be running dry?

I disconnected the hose from the bottom of the reservoir into a container and turned the engine on to let it flush through

 

[Algypan]

From post #2 I queried, note that the new hose should have the specification marked at intervals on the outside of the hose.


Not surprising it’s black as you reported earlier that it was overheating, question is why and what’s happened as a result.
Do you have a return flow now.
To flush the system you need to divert the oil from the return to a container and top up the reservoir and definitely not allowing the reservoir to run dry.
It sounds to me like you have disconnected the suction hose instead? I hope not or the pump will be running dry?

My apologies, I meant the top hose from the reservoir

I know you're trying to help me out and me throwing wrong information at you isn't helping, lol

 

[DXX]

My apologies, I meant the top hose from the reservoir

I know you're trying to help me out and me throwing wrong information at you isn't helping, lol

Just testing me!!!
Do you have return flow now?

 

[Algypan]

Just testing me!!!
Do you have return flow now?

Is that top hose I removed from the reservoir the return? I have that hose disconnected and now flowing into an empty container when the engine is running and I've been keeping it topped up so it doesn't run low