- Thread starter
- #21
Thank you. I'm always happy to get or find advice on the forum, so I try to contribute my 5 pence as good as possible.
BJ73 1985 Power steering pump rebuild (1 Viewer)
- Thread starter Felde
- Start date
-
- Tags
- power steering pump
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
- Thread starter
- #22
Now for hydraulic oil change and bleeding...
I constructed some aids to limit the mess..
You need to disconnect the return line and block the respective reservoir outlet. I used some 8mm PVC tube that I heated and molded on one end.
The return pipe comes from the bottom, so this copper angulated tubing comes handy. I actually made that for oil filling on axels and transfer case...
The power steering system takes mineral DEXON II fluid.
Regarding the fluid change, my 1st insight was: 1.5l of fluit at hand is not enough.
The system takes ~800 ml for a complete exchange. The reservoir holds about 300ml, so in theory about 3 turns are required.
The issue with having had the pump out is that you need to remove the air from the system. I discarded the used oil (actually only about 0.5I from the steering box and return line was left), which came out straight. The return line will spit out lots of foamy oil then.
I eventually endet up with 2l of new but foamy oil and air in the system, still.
The oil could be poured in again, but it takes hours for the foam bubbles to surface and the oil to clear. So either take your time or have about 3l of oil ready.
For the exchange/ filling procedure:
The engine needs to crank or run in order for the pump to work.
The manual says: "When return line starts to discharge fluid, stop engine IMMEDIATELY'.
This is absolutely essential! The pump suckles out the reservoir in less than 5sec!
Although stopping immediately at beginning of discharge, you will end up with almost the filling of the reservoir being discharged in total.
If you run the engine any longer, your reservoir is empty in no time and air is sucked in again. That sucks.
Forget about turning the wheel lock to lock at this stage. No time at all. For some lame engines even cranking may be enough...
It took me 6 reservoir fillings to get to oil with some bubbles, but not milky or foamy. That makes almost 2l of foamy oil discharged.
You can reconnect the return hose to the reservoir then. Make sure the return hose is full when reconnecting!
Bleeding the system is easy, as it is essentially self bleeding.
Top up the reservoir, start engine and now turn steering lock to lock several times.
Check the reservoir for level and foam. On excess foam you either need to wait for the foam to settle, or take it out using a syringe and replace with fresh oil.
But if oil was almost clear when reconnecting the return line, foam shouldn't appear any more.
Repeat procedure about 5 times.
Check reservoir level often on the first miles.
DONE
I constructed some aids to limit the mess..
You need to disconnect the return line and block the respective reservoir outlet. I used some 8mm PVC tube that I heated and molded on one end.
The return pipe comes from the bottom, so this copper angulated tubing comes handy. I actually made that for oil filling on axels and transfer case...
The power steering system takes mineral DEXON II fluid.
Regarding the fluid change, my 1st insight was: 1.5l of fluit at hand is not enough.
The system takes ~800 ml for a complete exchange. The reservoir holds about 300ml, so in theory about 3 turns are required.
The issue with having had the pump out is that you need to remove the air from the system. I discarded the used oil (actually only about 0.5I from the steering box and return line was left), which came out straight. The return line will spit out lots of foamy oil then.
I eventually endet up with 2l of new but foamy oil and air in the system, still.
The oil could be poured in again, but it takes hours for the foam bubbles to surface and the oil to clear. So either take your time or have about 3l of oil ready.
For the exchange/ filling procedure:
The engine needs to crank or run in order for the pump to work.
The manual says: "When return line starts to discharge fluid, stop engine IMMEDIATELY'.
This is absolutely essential! The pump suckles out the reservoir in less than 5sec!
Although stopping immediately at beginning of discharge, you will end up with almost the filling of the reservoir being discharged in total.
If you run the engine any longer, your reservoir is empty in no time and air is sucked in again. That sucks.
Forget about turning the wheel lock to lock at this stage. No time at all. For some lame engines even cranking may be enough...
It took me 6 reservoir fillings to get to oil with some bubbles, but not milky or foamy. That makes almost 2l of foamy oil discharged.
You can reconnect the return hose to the reservoir then. Make sure the return hose is full when reconnecting!
Bleeding the system is easy, as it is essentially self bleeding.
Top up the reservoir, start engine and now turn steering lock to lock several times.
Check the reservoir for level and foam. On excess foam you either need to wait for the foam to settle, or take it out using a syringe and replace with fresh oil.
But if oil was almost clear when reconnecting the return line, foam shouldn't appear any more.
Repeat procedure about 5 times.
Check reservoir level often on the first miles.
DONE
First, thank Felde for the info on the changing out fluids. Question, what Dexron II did you use? I am planning on doing this week when I change out my leaking PS pump. I've been reading and seems like Toyota 00718ATF00 ATF is the way to go. However, a number of the 80-series guys are running Valvoline Max Life ATF. Just looking at options.
- Thread starter
- #24
Hi
Thank you. Welcome
I did not use any Toyota original but LiquiMoly 3100 Lenkgetriebeöl (a German brand), which is specified as Dexro II D mineral and is specially dedicated to Servopumps.
Best regards Ralf
Thank you. Welcome
I did not use any Toyota original but LiquiMoly 3100 Lenkgetriebeöl (a German brand), which is specified as Dexro II D mineral and is specially dedicated to Servopumps.
Best regards Ralf
Okay another question, I was out trying to flush the pump using the method you mentioned above today. How long did you have to run the truck roughly before you started seeing fluid coming out the return? I had it running for a 5-10 seconds, shut off, then a few more, shut off again and the reservoir did not drain at all. I am wondering if the pump is not pulling anything. I disconnected the fill line from the top of the pump and it drained the reservoir then. Maybe I need to move the wheels to get things flowing.
Last edited:
- Thread starter
- #26
The pump has an extreme turnover. When I did it, I first startet the engine normal. The reservoir drained within seconds and as one reservoir filling is not enough to fill the circuit, it pulled in air and returned a nasty air-oil emulsion. But the return was instantaneous.
Thus my advice to turn the engine on only for a few seconds to manage to not drain the reservoir completely and top it up before air gets sucked in.
If you are not sure whether the pump pumps, you may pull the return line at the reservoir and put it in a bottle. A filling of the rervoir should end up there within a few seconds.
My understanding of the function is: The pump always pumps in circulation, basically trough a bypass in the steering box. Only when steering, a vent leads fluid into the servo mechanism to provide power to assist steering. So, steering the wheels is required to bleed all of the mechanism and provide proper function, but pump and return flow in general should be unaffected. But give it a try; I may be wrong.
Good Luck Ralf
Thus my advice to turn the engine on only for a few seconds to manage to not drain the reservoir completely and top it up before air gets sucked in.
If you are not sure whether the pump pumps, you may pull the return line at the reservoir and put it in a bottle. A filling of the rervoir should end up there within a few seconds.
My understanding of the function is: The pump always pumps in circulation, basically trough a bypass in the steering box. Only when steering, a vent leads fluid into the servo mechanism to provide power to assist steering. So, steering the wheels is required to bleed all of the mechanism and provide proper function, but pump and return flow in general should be unaffected. But give it a try; I may be wrong.
Good Luck Ralf
That makes sense. I have mine setup like you did with the reservoir attached to the pump, and the return blocked and hose into a bottle. When I start the truck nothing is coming out of the return and the reservoir is not draining at all. I suspect I might have a problem somewhere. I tried jacking it up and turning the wheels as well. I am going to try putting the return back on and see if it at least circulates and makes the reservoir fluid change.
- Thread starter
- #28
If you have the return line in the bottle and the engine running and move the wheels AND nothing is coming out: Either a) the pump is not pumping or b) the steering box is blocking the return.
To check: Remove the hose at the pump outlet and place that end into a container.
Turn engine over with starter (just seconds). Should give output with pressure (Cover container and fixate the hose to avoid spill). If not: Pump dead. If output: Steering box blocked.
Unfortunately there also is an option c): Both.
Not sure how the pump would hold up if it can't get rid of fluid and pressure. It is a vane pump. The vanes might take damage.
Good Luck Ralf
To check: Remove the hose at the pump outlet and place that end into a container.
Turn engine over with starter (just seconds). Should give output with pressure (Cover container and fixate the hose to avoid spill). If not: Pump dead. If output: Steering box blocked.
Unfortunately there also is an option c): Both.
Not sure how the pump would hold up if it can't get rid of fluid and pressure. It is a vane pump. The vanes might take damage.
Good Luck Ralf
