Long over due Power steering flush.....
08-30-2015, 09:45 AM
#21
TECH Enthusiast
When the wheels are on the ground and the vehicle is not moving the rack sees huge inputs loads because you are trying to overcome the effects of static friction of the tires on the ground.
When the vehicle/wheels are moving on the ground you are only overcoming the effects of rolling friction which is much less force than static friction.
So like nikdsc5 mentioned when he turned the pump to lock, fluid shot out everywhere because the pressures needed to provide assist with the wheel on the ground is much greater than if the wheels were up in the air.
At the end of the day you are not damaging anything by doing it with the wheels on the ground, you are just putting more stress on the rack and steering arms by doing so. So potentially in the long run you may wear out these components sooner.
It's generally good practice to never turn your steering wheel very much without the vehicle moving slightly.
09-03-2015, 02:44 PM
#23
Here's the method I've used on all of my cars to help flush out the old fluid:
- Disconnect the return from the reservoir and plug the return bung, as you did.
- Thread a bolt into the snout of the PS pump shaft.
- Use a bit driver and a universal joint on a drill to drive the pump (obviously with the belt removed) with one hand, while topping off the reservoir with fluid with the other hand. You can control the speed of the pump pretty easily, so it's not hard to keep the pump from sucking the reservoir dry.
- Watch for clean fluid to issue from the return line.
I honestly don't know if that method is any better, but in my head it makes sense to have the pump push fluid through the system.
- Disconnect the return from the reservoir and plug the return bung, as you did.
- Thread a bolt into the snout of the PS pump shaft.
- Use a bit driver and a universal joint on a drill to drive the pump (obviously with the belt removed) with one hand, while topping off the reservoir with fluid with the other hand. You can control the speed of the pump pretty easily, so it's not hard to keep the pump from sucking the reservoir dry.
- Watch for clean fluid to issue from the return line.
I honestly don't know if that method is any better, but in my head it makes sense to have the pump push fluid through the system.
How often are you doing this? (how many miles)
09-03-2015, 11:52 PM
#24
TECH Addict
iTrader: (19)
Join Date: Aug 2007
Location: Where the Navy tells me to go
Posts: 2,398
Received 106 Likes
on
88 Posts
I've never really had any set interval for PS fluid change, I suppose I'm pretty reactive on that particular bit of maintenance (flush it when the systems starts to misbehave). This thread has prompted me to think that my PS system is probably due for a flush - might see about doing it this weekend.
Oh, and from personal experience, don't go thinking that you can just start the engine for a couple seconds and then shut it off (rather than driving the pump with a drill). Turns out that pump is moving a surprising amount of fluid, even at idle, and you will just manage to make a mess.
Oh, and from personal experience, don't go thinking that you can just start the engine for a couple seconds and then shut it off (rather than driving the pump with a drill). Turns out that pump is moving a surprising amount of fluid, even at idle, and you will just manage to make a mess.
09-04-2015, 08:44 AM
#25
Here's the method I've used on all of my cars to help flush out the old fluid:
- Disconnect the return from the reservoir and plug the return bung, as you did.
- Thread a bolt into the snout of the PS pump shaft.
- Use a bit driver and a universal joint on a drill to drive the pump (obviously with the belt removed) with one hand, while topping off the reservoir with fluid with the other hand. You can control the speed of the pump pretty easily, so it's not hard to keep the pump from sucking the reservoir dry.
- Watch for clean fluid to issue from the return line.
I honestly don't know if that method is any better, but in my head it makes sense to have the pump push fluid through the system.
- Disconnect the return from the reservoir and plug the return bung, as you did.
- Thread a bolt into the snout of the PS pump shaft.
- Use a bit driver and a universal joint on a drill to drive the pump (obviously with the belt removed) with one hand, while topping off the reservoir with fluid with the other hand. You can control the speed of the pump pretty easily, so it's not hard to keep the pump from sucking the reservoir dry.
- Watch for clean fluid to issue from the return line.
I honestly don't know if that method is any better, but in my head it makes sense to have the pump push fluid through the system.
10-18-2015, 11:23 AM
#26
Got inspired by this thread and decided to knock this out today. I meant to take a picture of my fluid before it had too much clean fluid in it, but I forgot. It wasn't as bad as Nik's, but it was definitely the original fluid at 87k miles. Either way, I feel better. With the wheels in the air, the fluid did not spurt out violently and it was just much easier overall to flush it
10-18-2015, 02:31 PM
#27
I've never really had any set interval for PS fluid change, I suppose I'm pretty reactive on that particular bit of maintenance (flush it when the systems starts to misbehave). This thread has prompted me to think that my PS system is probably due for a flush - might see about doing it this weekend.
Oh, and from personal experience, don't go thinking that you can just start the engine for a couple seconds and then shut it off (rather than driving the pump with a drill). Turns out that pump is moving a surprising amount of fluid, even at idle, and you will just manage to make a mess.
Oh, and from personal experience, don't go thinking that you can just start the engine for a couple seconds and then shut it off (rather than driving the pump with a drill). Turns out that pump is moving a surprising amount of fluid, even at idle, and you will just manage to make a mess.
10-19-2015, 01:52 PM
#28
Figure I'll add in my method... I pulled the return hose from the bottom of the reservoir and capped the barb fitting. I plugged in the hand pump I use for trans fluid changes to the return hose, and pulled the dirty fluid out from that hose through the pump as I poured clean fluid into the reservoir. I didn't bother with spinning the pump or cycling the rack, didn't even raise the car off the ground. I typically swap out the reservoir with fresh fluid about three times a year so my system wasn't completely stagnant before this most recent flush. I was done in about 15min. Hardest part was cleaning up the mess that pulling the the return hose created.
06-03-2016, 09:27 PM
#29
TECH Addict
iTrader: (19)
Join Date: Aug 2007
Location: Where the Navy tells me to go
Posts: 2,398
Received 106 Likes
on
88 Posts
So, 7 months or so after saying "I might see about doing it this weekend", I finally got around to changing out the PS fluid. 
Got a track event on Monday/Tuesday, so I wanted to get fresh fluid in there before that. It definitely needed it - the stuff that came out stank and was nice and dark.
To my surprise, the pump shaft is threaded to 3/8"-16. Add that one to the short list of random things that are still imperial thread on a metric car.
Got a track event on Monday/Tuesday, so I wanted to get fresh fluid in there before that. It definitely needed it - the stuff that came out stank and was nice and dark.To my surprise, the pump shaft is threaded to 3/8"-16. Add that one to the short list of random things that are still imperial thread on a metric car.
06-05-2016, 01:31 PM
#30
I stumbled across another method for replacing the power steering fluid more frequently. With my old fluid yse cooler it leaked enough that I had to constantly top it off. It's like an auto flush!
Now that I put a b&m cooler in thouh I will have to remember to actually change it now...
Now that I put a b&m cooler in thouh I will have to remember to actually change it now...