Another Power Steering Pump - 4 Month Program

[2001LC]

I got a lot of air bubbles out by turning steering while the wheels were off the ground with the engine off. When it finally stopped bubbling, then I started the engine.

Lack detail I ask for, on flushing & bleeding. Sorry I can't help!

 

[OwnerCS]

Lack detail I ask for, on flushing & bleeding. Sorry I can't help!

I evacuate the reservoir using a pump. Bleeding with wheels off the ground and lock to lock turns brings out bubbles. After the bubbles are gone and I've primed the pump by turning it manually, I install the belt and repeat the procedure with wheels off the ground.

 

[2001LC]

I do flush, a little different.

1. Place front on jack-stands
2. Poor out reservoir. The reason I poor out, is to get return line off, from empty reservoir. Also, so can inspect reservoir if needed. If reservoir dirty I remove and clean at this point.
3. Disconnect return line from reservoir and run to catch can.
4. Plug reservoir return nipple (otherwise fluid runs out it reservoir).
5. Fill reservoir with M1 ATF (suction hose is attached). If replacing Vane, lines, hoses or Rack. I do not fill reservoir, unit replacements parts in.
6. Place cap on reservoir. The stem on cap is not a level stick, it's a valve.
7. Turn steering wheel lock to lock slowly, holding at lock 3 seconds or more. You can see level drop as held at lock. Hold at lock until fluid stops dropping. If system has been drained, turning steering wheel faster at first, helps get fluid moving. If draining system to replace parts, keep turn lock to lock until no fluid comes out return line. Step is more about if draining system.
8. Add fluid as needed, to keep level from dropping below bottom of reservoir.
9. Watch catch can until fluid runs clear. Time so that reservoir level near bottom, to reduce wasting good fluid.
10. Attach return line to reservoir and fill with M1 ATF to high cold mark (plus a little above mark, save time).
11. Turn steering wheel slowly lock to lock holding at lock 3 seconds or more. Again watch reservoir and hold at lock until level stops dropping. Then turn in other discretion holding at lock. Repeat at least 3 time, more if needed. Keep add fluid, as level drops below cold low line. Topping back up to cold high line.
12. Take off jack-stands, putting tires on ground.
13. Start engine and turn steering wheel slowly lock to lock, hold at lock. Repeat at least 3 times. Top fluid as needed.
14. If foaming/bubbles seen in reservoir, repeat procedure. Best to start again with engine off, tire off the ground to protect the pump in event dry (air bubble).

Above a two step bleed, just as FSM direct us..

1. Step one is a low pressure flush/bleed. In which no resistance from tires on ground or pressure from pump. The rack is pushing the fluid out. When the system had/has fluid removed or air in it, this safely fills the system. Most importantly the pump, which we don't want to run dry.
2. Step two is the high pressure bleed. Tires on ground creates resistance and pump gives high pressure. Up to this point, ~98% of air out from low pressure bleed, and we can safely run pump. After step two, once forming/bubbles stops appearing in reservoir, air is out, we're good to go.

It's best to avoid starting engine until step one complet and tires back on the ground ready for step two.

 

[OwnerCS]

I do flush, a little different.

1. Place front on jack-stands
2. Poor out reservoir. The reason I poor out, is to get return line off, from empty reservoir. Also, so can inspect reservoir if needed. If reservoir dirty I remove and clean at this point.
3. Disconnect return line from reservoir and run to catch can.
4. Plug reservoir return nipple (otherwise fluid runs out it reservoir).
5. Fill reservoir with M1 ATF (suction hose is attached). If replacing Vane, lines, hoses or Rack. I do not fill reservoir, unit replacements parts in.
6. Place cap on reservoir. The stem on cap is not a level stick, it's a valve.
7. Turn steering wheel lock to lock slowly, holding at lock 3 seconds or more. You can see level drop as held at lock. Hold at lock until fluid stops dropping. If system has been drained, turning steering wheel faster at first, helps get fluid moving. If draining system to replace parts, keep turn lock to lock until no fluid comes out return line. Step is more about if draining system.
8. Add fluid as needed, to keep level from dropping below bottom of reservoir.
9. Watch catch can until fluid runs clear. Time so that reservoir level near bottom, to reduce wasting good fluid.
10. Attach return line to reservoir and fill with M1 ATF to high cold mark (plus a little above mark, save time).
11. Turn steering wheel slowly lock to lock holding at lock 3 seconds or more. Again watch reservoir and hold at lock until level stops dropping. Then turn in other discretion holding at lock. Repeat at least 3 time, more if needed. Keep add fluid, as level drops below cold low line. Topping back up to cold high line.
12. Take off jack-stands, putting tires on ground.
13. Start engine and turn steering wheel slowly lock to lock, hold at lock. Repeat at least 3 times. Top fluid as needed.
14. If foaming/bubbles seen in reservoir, repeat procedure. Best to start again with engine off, tire off the ground to protect the pump in event dry (air bubble).

Above a two step bleed, just as FSM direct us..

1. Step one is a low pressure flush/bleed. In which no resistance from tires on ground or pressure from pump. The rack is pushing the fluid out. When the system had/has fluid removed or air in it, this safely fills the system. Most importantly the pump, which we don't want to run dry.
2. Step two is the high pressure bleed. Tires on ground creates resistance and pump gives high pressure. Up to this point, ~98% of air out from low pressure bleed, and we can safely run pump. After step two, once forming/bubbles stops appearing in reservoir, air is out, we're good to go.

It's best to avoid starting engine until step one complet and tires back on the ground ready for step two.

Thanks for the detailed response, Paul! I'll give it a run.

 

[OwnerCS]

I do flush, a little different.

1. Place front on jack-stands
2. Poor out reservoir. The reason I poor out, is to get return line off, from empty reservoir. Also, so can inspect reservoir if needed. If reservoir dirty I remove and clean at this point.
3. Disconnect return line from reservoir and run to catch can.
4. Plug reservoir return nipple (otherwise fluid runs out it reservoir).
5. Fill reservoir with M1 ATF (suction hose is attached). If replacing Vane, lines, hoses or Rack. I do not fill reservoir, unit replacements parts in.
6. Place cap on reservoir. The stem on cap is not a level stick, it's a valve.
7. Turn steering wheel lock to lock slowly, holding at lock 3 seconds or more. You can see level drop as held at lock. Hold at lock until fluid stops dropping. If system has been drained, turning steering wheel faster at first, helps get fluid moving. If draining system to replace parts, keep turn lock to lock until no fluid comes out return line. Step is more about if draining system.
8. Add fluid as needed, to keep level from dropping below bottom of reservoir.
9. Watch catch can until fluid runs clear. Time so that reservoir level near bottom, to reduce wasting good fluid.
10. Attach return line to reservoir and fill with M1 ATF to high cold mark (plus a little above mark, save time).
11. Turn steering wheel slowly lock to lock holding at lock 3 seconds or more. Again watch reservoir and hold at lock until level stops dropping. Then turn in other discretion holding at lock. Repeat at least 3 time, more if needed. Keep add fluid, as level drops below cold low line. Topping back up to cold high line.
12. Take off jack-stands, putting tires on ground.
13. Start engine and turn steering wheel slowly lock to lock, hold at lock. Repeat at least 3 times. Top fluid as needed.
14. If foaming/bubbles seen in reservoir, repeat procedure. Best to start again with engine off, tire off the ground to protect the pump in event dry (air bubble).

Above a two step bleed, just as FSM direct us..

1. Step one is a low pressure flush/bleed. In which no resistance from tires on ground or pressure from pump. The rack is pushing the fluid out. When the system had/has fluid removed or air in it, this safely fills the system. Most importantly the pump, which we don't want to run dry.
2. Step two is the high pressure bleed. Tires on ground creates resistance and pump gives high pressure. Up to this point, ~98% of air out from low pressure bleed, and we can safely run pump. After step two, once forming/bubbles stops appearing in reservoir, air is out, we're good to go.

It's best to avoid starting engine until step one complet and tires back on the ground ready for step two.

Cleaned the reservoir and followed the flush and bleed procedure using M1. The bleeding procedure is good. It took roughly 12 lock-to-lock cycles to get all of the bubbles out. The pump was quiet when I started it up afterward.

Unfortunately, the whine returns when the engine is running over 1,300 RPM. I talked to my son Adam who confirmed this is the same whine during the July Colorado trip. Adam suspects the problem is with rack valves that are not allowing fluid to flow fast enough through the pump. So the pump starts to cavitate at higher RPM and cooks fluid. I'm beginning to accept that I may need to buy another rack. The rack is an OEM that is roughly two years old. If the rack really is the problem, it started not long after installation. The 1st pump problem first appeared after the Colorado trip in 2021.

Offroading season is here. I will limp along with this pump and hopefully get 2 months out of it before I put the truck up on jack stands to change the rack in late November and December. I will also change PS fluid between offroad trips to keep it fresh.

 

[awesomeissquid]

Cleaned the reservoir and followed the flush and bleed procedure using M1. The bleeding procedure is good. It took roughly 12 lock-to-lock cycles to get all of the bubbles out. The pump was quiet when I started it up afterward.

Unfortunately, the whine returns when the engine is running over 1,300 RPM. I talked to my son Adam who confirmed this is the same whine during the July Colorado trip. Adam suspects the problem is with rack valves that are not allowing fluid to flow fast enough through the pump. So the pump starts to cavitate at higher PRM and cooks fluid. I'm beginning to accept that I may need to buy another rack. The rack is an OEM that is roughly two years old. If the rack really is the problem, it started not long after installation. The 1st pump problem first appeared after the Colorado trip in 2021.

Offroading season is here. I will limp along with this pump and hopefully get 2 months out of it before I put the truck up on jack stands to change the rack in late November and December. I will also change PS fluid between offroad trips to keep it fresh.

If it does end up being the rack maybe talk with the dealer you bought it from to see if they can do anything to help since it would then be obvious a manufacturing defect.

 

[OwnerCS]

If it does end up being the rack maybe talk with the dealer you bought it from to see if they can do anything to help since it would then be obvious a manufacturing defect.

That would be great! Especially considering the cost.

 

[Eyedaho]

Cleaned the reservoir and followed the flush and bleed procedure using M1. The bleeding procedure is good. It took roughly 12 lock-to-lock cycles to get all of the bubbles out. The pump was quiet when I started it up afterward.

Unfortunately, the whine returns when the engine is running over 1,300 RPM. I talked to my son Adam who confirmed this is the same whine during the July Colorado trip. Adam suspects the problem is with rack valves that are not allowing fluid to flow fast enough through the pump. So the pump starts to cavitate at higher RPM and cooks fluid. I'm beginning to accept that I may need to buy another rack. The rack is an OEM that is roughly two years old. If the rack really is the problem, it started not long after installation. The 1st pump problem first appeared after the Colorado trip in 2021.

Offroading season is here. I will limp along with this pump and hopefully get 2 months out of it before I put the truck up on jack stands to change the rack in late November and December. I will also change PS fluid between offroad trips to keep it fresh.

Do you get any foaming in the reservoir at all when you hear the whining noise?

 

[OwnerCS]

Do you get any foaming in the reservoir at all when you hear the whining noise?

Yes. I can see fluid circulating and foaming does happen. The foaming seems to be worse when the cap is off.

 

[OwnerCS]

As a side note, the steering is very easy to turn now. Better than I remember. Almost like the Chrysler power steering from the 1960s. But it whines like a 1995 F150.

 

[Eyedaho]

Yes. I can see fluid circulating and foaming does happen. The foaming seems to be worse when the cap is off.

I have had a similar issue on another vehicle with a small leak on the suction side of the PS piping, which allowed air to be sucked into the system. It caused whining and foaming, and increased with RPMs (more suction). I think there are only the two connections on the suction side between the pump and reservoir, but it's possible that the o-ring seal on the low pressure (return) side of the rack could cause a similar issue?

 

[OwnerCS]

I have had a similar issue on another vehicle with a small leak on the suction side of the PS piping, which allowed air to be sucked into the system. It caused whining and foaming, and increased with RPMs (more suction). I think there are only the two connections on the suction side between the pump and reservoir, but it's possible that the o-ring seal on the low pressure (return) side of the rack could cause a similar issue?

I'll try to make a video. I'm working with a fairly new OEM hose.

 

[Bisho]

I have had a similar issue on another vehicle with a small leak on the suction side of the PS piping, which allowed air to be sucked into the system. It caused whining and foaming, and increased with RPMs (more suction). I think there are only the two connections on the suction side between the pump and reservoir, but it's possible that the o-ring seal on the low pressure (return) side of the rack could cause a similar issue?

Our racks are flared fittings - no O-rings.

 

[Eyedaho]

Our racks are flared fittings - no O-rings.

Oh yeah, I guess the low pressure side of mine ('99) is a flare, and gasket on the high pressure side. It's been a while since I swapped out my rack. So might just be able to snug down the return side at the rack.

 

[2001LC]

I fear you've large debris in system. The 2 components not replaced a 2nd time are the reservoir and rack IIRC.

You installed aftermarket reservoir. Did you ever replace with OEM reservoir?

When I install racks. I pull out the rubber caps from the in & out lines threaded ports of new, to inspect threads. I then place rubber caps back in ports, to keep clean & protect threads. It possible debris during manufacture got in rack or seal was damage, but not likely. More likely during install, something got in. You can have pressure testing done on rack. Likely to find a shop with the tools/gauges while rack in vehicle, Dealership best bet. Or pull the rack and take to re-builder for testing. They can rebuild your rack and use your rack and its OEM TRE and boots. But cost of new, would only be a few hundred more.

In one picture of fluid that was changed and then drain into catch can, where it turned black. It looks like thick sludge in bottom of catch can. This indicates a contaminate in fluid. It also has particles in sludge. If those are particles and not just bubbles, they may be metal. If metal, only two places it could come from. Pump or rack. 3 or 4 defective Toyota vane pumps in a rows, is nearly impossibly. But if pump over-torqued on engine block, they could getting be damaged.

BTW: In every pictures posted of reservoir, it was over filled.

 

[OwnerCS]

I fear you've large debris in system. The 2 components not replaced a 2nd time are the reservoir and rack IIRC.

You installed aftermarket reservoir. Did you ever replace with OEM reservoir?

When I install racks. I pull out the rubber caps from the in & out lines threaded ports of new, to inspect threads. I then place rubber caps back in ports, to keep clean & protect threads. It possible debris during manufacture got in rack or seal was damage, but not likely. More likely during install, something got in. You can have pressure testing done on rack. Likely to find a shop with the tools/gauges while rack in vehicle, Dealership best bet. Or pull the rack and take to re-builder for testing. They can rebuild your rack and use your rack and its OEM TRE and boots. But cost of new, would only be a few hundred more.

In one picture of fluid that was changed and then drain into catch can, where it turned black. It looks like thick sludge in bottom of catch can. This indicates a contaminate in fluid. It also has particles in sludge. If those are particles and not just bubbles, they may be metal. If metal, only two places it could come from. Pump or rack. 3 or 4 defective Toyota vane pumps in a rows, is nearly impossibly. But if pump over-torqued on engine block, they could getting be damaged.

BTW: In every pictures posted of reservoir, it was over filled.

The aftermarket reservoir was replaced long ago with a new OEM. Sunsong hoses were replaced with OEM during the last episode. Pump torqued to 13 ft lbs.

Everyting in the area was cleaned atter old rack front diff, and many other parts were removed. Cap plugs were removed after rack was installed.

 

[2001LC]

So was it metal particles in sludge? "In one picture of fluid that was changed and then drain into catch can, where it turned black. It looks like thick sludge in bottom of catch can. This indicates a contaminate in fluid. It also has particles in sludge."

 

[OwnerCS]

So was it metal particles in sludge? "In one picture of fluid that was changed and then drain into catch can, where it turned black. It looks like thick sludge in bottom of catch can. This indicates a contaminate in fluid. It also has in sludge."

I have the old cooked fluid from two different timeframes in jars that I planned to send to Blackstone Labs. The dark sludge was from the bottom of the reservoir that had built up over 3 to 4 months.

I'll look to get a magnet and run it through the sludge to find any metal particles.

Oddly, the sludge feels like very fine dust that is suspended in ATF. It felt gritty. It's been years since I have worked with a car that has burnt oil sludge to try to compare.
At first glance, the sludge in the ATF looks more like it has been cooked until it started to burn and change composition.

 

[OwnerCS]

So was it metal particles in sludge? "In one picture of fluid that was changed and then drain into catch can, where it turned black. It looks like thick sludge in bottom of catch can. This indicates a contaminate in fluid. It also has particles in sludge."

One other item. I made the mistake of touching the pump at the fitting where lines from the reservoir connect for just a few seconds after it had been running for 10 to 15 minutes. I got a burn and blister like I had touched the exhaust manifold. I'm curious to get a temp gauge that will display up to 300 degrees.

 

[Eyedaho]

I have the old cooked fluid from two different timeframes in jars that I planned to send to Blackstone Labs. The dark sludge was from the bottom of the reservoir that had built up over 3 to 4 months.

I'll look to get a magnet and run it through the sludge to find any metal particles.

Oddly, the sludge feels like very fine dust that is suspended in ATF. It felt gritty. It's been years since I have worked with a car that has burnt oil sludge to try to compare.
At first glance, the sludge in the ATF looks more like it has been cooked until it started to burn and change composition.

That's what I was picturing when I asked about foaming. Since you have changed all of the components and have been much more diligent about fluid changes than most folks, I thought maybe fluid aeration was causing excessive heat and breaking down the fluid. I have no idea if that's the case, but seemed like a possibility to me. A lab analysis might help with that determination? I hope you get it sorted, since I know it has been plaguing you for a while!