turdmagnet
Registered Member
I'm going to change the power steering pump in my '74 Blazer. Do I need to use ATF, 75-90 gear lube, or something else for power steering fluid?
CK5
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Brace yourself for a dumb question...
- Thread starter turdmagnet
- Start date
JEBSR
1/2 ton status
Either ATF or power steering fluid.
Sorry if this is a hi-jack, but brace yourself for an even dumber question:
If I simply wanna change the fluid, where and how is the easiest and best way to drain the old one?? The manual says it never has to be changed and thus gives no further information on the subject, but c'mon, if it hasn't been changed for 20 years...? Bound to be some water and **** in there...
If I simply wanna change the fluid, where and how is the easiest and best way to drain the old one?? The manual says it never has to be changed and thus gives no further information on the subject, but c'mon, if it hasn't been changed for 20 years...? Bound to be some water and **** in there...
What do shop or service manuals say?
I've heard disaster stories with using ATF. Something about the stuff in it causing the seals to swell to which they leak. My leaks were at the steering gear box and it was a new rebuilt unit. After switching fluids, the leakage stopped somewhat.
I learned this from my K30 as I put ATF in it for years. And then a mechanic friend explained to me that ATF is for tranny's only. Use the correct power steering fluid as thats what they're for.
I haven't seen anymore leaks since I poured the correct fluid in it.
I've heard disaster stories with using ATF. Something about the stuff in it causing the seals to swell to which they leak. My leaks were at the steering gear box and it was a new rebuilt unit. After switching fluids, the leakage stopped somewhat.
I learned this from my K30 as I put ATF in it for years. And then a mechanic friend explained to me that ATF is for tranny's only. Use the correct power steering fluid as thats what they're for.
I haven't seen anymore leaks since I poured the correct fluid in it.
CDA 455
3/4 ton status
AuH2O said:
There is no dumb questions, only un-asked ones. (And this isn't Pirate)
!I've ask this same question and it appears there isn't any 'official answer'.
So my answer is this:
Suck all the fluid out of the PS pump via an Evac. sys. Maybe even unscrew a hose from the box and evac. there too.
And then screw hose back in and proceed with PS fluid-fill and priming.
Like brake fluid and ATF, PS fluid should be changed approx. every 15,000 to 30,000 miles because it has to deal with heat and pressure while the vehicle is running.
Yet for some reason, there is NO provisions for draining or even bleeding the PS system.
As a comparable, etc.:
Even synthetic motor oil has to be changed. Why? Because it still picks up crap in the system (metal particles, water, etc.). The biggest thing about synthetic oil is that it won't break down like petroleum oil. BUT, you still have to change it!
h0wl0ngcanitbe
1/2 ton status
What do you mean by sucking the fluid out? do i just literally pop the cap and suction the fluid out by hand? and if so how much should i be pulling out as in for my 86 K5 how much steering fluid is supposed to be in their? and then do i just fill er up and repaet the process till its clean?
yettieman95
Registered Member
At our shop we use a type of rear diff. pump to suck the old fluid out. I've also seen a guy make a suction grease gun / pump thingy that works really good.... but I'm not sure how he did it. Also after adding new fluid and making sure it up to level i would start the truck up and turn the steering wheel side to side to flush the new fluid into where you couldn't get the old fluid out of. Then change the fluid again... Then you'll have that new car scent... or new power steering fluid scent which I don't think smells that good.
Leper
1/2 ton status
I use 808 tractor oil. It doesn't heat up as much as regular fluid.
An easy way to change the fluid is to stick the return line to the pump in a 5 gallon bucket of fluid. Take the return line from the gearbox and put it in a pan. Start the truck and run it until the fluid is clean.
An easy way to change the fluid is to stick the return line to the pump in a 5 gallon bucket of fluid. Take the return line from the gearbox and put it in a pan. Start the truck and run it until the fluid is clean.
I take the return line off at the pump and put it into a container big enough to hold all the fluid. Turn the engine on and turn the wheels lock to lock (keeping the reservoir full with new PS fluid) until fresh fluid comes out. It'll make a mess. Once the fluid is clear, shut off the engine, re-attach the line and turn the wheels nearly lock to lock (with engine off) to help purge any bubbles that might still be in there. Top off the reservoir and call it good.
h0wl0ngcanitbe
1/2 ton status
that sounds like the most efficent way of doin it but im not aware of said return lines im gonna post a pic of my steering colomn and gear box or rather what i think my gear box is and see if you can point out which ojne it is?
is it 1,2,3, or 4? or any of those at all?
is it 1,2,3, or 4? or any of those at all?
that sounds like the most efficent way of doin it but im not aware of said return lines im gonna post a pic of my steering colomn and gear box or rather what i think my gear box is and see if you can point out which ojne it is?
is it 1,2,3, or 4? or any of those at all?
Should be #2, if that's the one that has a clamp on it.
In a hydraulic system like your power steering, there's a pressure side, from the pump, where the fluid is compressed to the tune of hundreds of PSI, then the load, where the work is done (in this case the steering box), and finally the return side, where the pressure is considerably less 'cuz it got used up as mechanical energy pushing the steering around. [Hydro engineering types will grimace at my gross oversimplification, but it's the general idea.]
You'll notice that the pressure hose has the crimped ends with the threaded connectors, 'cuz it has to withstand the crazy high pressure and your basic hose clamp would go flying off. The return hose, however, can use the hose clamp 'cuz it's lower pressure. That's the hose that carries the fluid OUT of the box, and recirculates it back into the pump for it to pressurize and send back to the box.
Anyway, more than a direct answer, it's the "teaching you to fish" answer -- and gives you some insight into the PS system.
(NB: The hydroboost system uses the PS system to power the brake assist, so there are hoses linking the steering box to the brake booster, and IIRC a return line from each, so it's more complicated ... but is basically the same idea.)
Other thoughts on this thread:
PS fluid is a variety of hydraulic fluid. So is ATF, but it does have differena additives. There are aftermarket PS components that specify the use of ATF, but for your normal parts-house replacement parts, use power steering fluid in the power steering system.
Once the fluid is replaced, the system will need to be bled. There are a number of methods you can use; one such is described in a few threads here, and I grabbed the PDF for re-use:
http://www.slosh.com/ck5/bleedinginstructions.pdf
To the OP, I would question why you're replacing the pump. If it's squealing, it may just be low on fluid; if it's leaking, I'd suspect the hoses instead or in addition to the pump. While you're in there is a good time to at the least inspect the hoses, if not replace them outright. Look for cracks in the rubber at the crimp connections. (OTOH, pumps do wear out, so it's not unreasonable to replace, and you may be installing hydroboost or somesuch that requires changing the pump.)
-- A
h0wl0ngcanitbe
1/2 ton status
Thankyou so much man this is all very helpfull, I hope im not being too much of a pain!
I'm going to say number 2 as well, for the reasons dremu said. One thing I forgot to mention is to put a plug of some kind in the return fitting on the pump, or you'll just suck air into the pump and ruin it. Powersteering pumps can go prolly a minute at the most before they fail, so do your best to keep air out of the system.that sounds like the most efficent way of doin it but im not aware of said return lines im gonna post a pic of my steering colomn and gear box or rather what i think my gear box is and see if you can point out which ojne it is?
is it 1,2,3, or 4? or any of those at all?
Knew I forgot something.I can't remember, but the original idea was to pump new fluid in, right? I'd put a hose into a jar of PS fluid and put that into the return line, so as to keep fluid flowing through... or yeah, maybe you could cap it, then keep it filled from the top?
-- A
Dafey
1/2 ton status
IIRC from school ATF has detergents in it,that tear up the seals used in PS Pumps.
Yeah, just pour more in as needed. You disconnect the return line at the pump and put that in an empty container, cap the opening on the pump, and pour new fluid in the reservior.
I can't remember, but the original idea was to pump new fluid in, right? I'd put a hose into a jar of PS fluid and put that into the return line, so as to keep fluid flowing through... or yeah, maybe you could cap it, then keep it filled from the top?
-- A
h0wl0ngcanitbe
1/2 ton status
ya im told to use the stuff from the gm parts counter at any ol local chevy dealership thats labeled power steering fluid.
