Using A Fluid Extractor On A Rear End ?

[JeffKeryk]

Has anyone done this? I don't have one. And I wouldn't use one for an oil change. But for something like a rear end, or a power steering, or brake fluid change they would seem to have a degree of usefulness. If any of you guys have done this, how did it work out?

For brakes it wouldn't be as effective as using a bleeder system. But if you sucked the reservoir down low enough, but without getting air in the system, then refill with fresh fluid, it would help. Then just repeat it a few times a month, and you would be getting the bulk of it out. Brake fluid and rear end oil is fairly cheap.

Never used it for a rear, but as others have said, get the gear oil hot. Why American car companies do not install a drain plug is beyond me.

The MityVac excels on PS systems. Just suck out the reservoir, pull the return line, plug the port and stick the extractor into the return line. Suck all the fluid out. Sometimes I remove and brake spray the reservoir. Fill 'er and continue to suck new fluid through. Let it run low, replace the return line and fill. Let it run a little to bleed, then recheck level.

Brakes? Not so sure. I do suck out master and refill before normal bleeding.

 

[ejes]

Just remember brake fluid does not circulate

This is correct. Water and brake fluid are miscible fluids and are subject to the laws of diffusion. Every time you apply the brake, it aids diffusion.

 

[paulo57509]

The rear axle on my '63 Bonneville didn't have a drain plug. You had to pull the axles and remove the carrier from the housing if you wanted to drain it.

I don't recommend this if you're pressed for time, but it's a viable alternative:

I took a length of 3/8" fuel hose; removed the fill plug and siphoned the lube out of the housing. I started mid-morning and it was drained by around 4pm. Not completely empty but enough new lube was pumped in.

Back then, there were no extractors or MityVac things around.

 

[eljefino]

This is correct. Water and brake fluid are miscible fluids and are subject to the laws of diffusion. Every time you apply the brake, it aids diffusion.

There is a tiny, tiny hole between the reservoir and MC that's only uncovered when the pedal is fully up. This diffusion everyone hopes happen is like opening a window 1/8 of an inch to air out a stinky flatus from your room.

Doing it wrong by only changing the reservoir is a disservice to anyone else who looks at the car, and assumes the brake fluid has been maintained (properly) because the visible part looks good. It's defrauding oneself and close to defrauding others.

 

[ripcord]

I never use my extraction pump on brake MC's as I don't want to contaminate my brake fluid with petroleum and we're not supposed to mix brake fluid with engine oil. I just use a turkey baster.

I've used the extractor on differentials many times, like on our Expedition's front diff where you need to disconnect suspension and steering components to reach all the cover bolts. As mentioned, it's pretty slow when the oil is cold.

 

[wlk]

I have that pump, but admittingly I've never used it. I was thinking more of this one....

https://www.harborfreight.com/23-gallon-manual-fluid-extractor-62643.html

Has anyone done this? I don't have one. And I wouldn't use one for an oil change. But for something like a rear end, or a power steering, or brake fluid change they would seem to have a degree of usefulness. If any of you guys have done this, how did it work out?

For brakes it wouldn't be as effective as using a bleeder system. But if you sucked the reservoir down low enough, but without getting air in the system, then refill with fresh fluid, it would help. Then just repeat it a few times a month, and you would be getting the bulk of it out. Brake fluid and rear end oil is fairly cheap.

Have that HF extractor as well and works great. I have used it on an Expedition's front axle as others have mentioned due to no drain bolt. I use a very flexible silicone hose for diffs as it is easier to manipulate down into the diff.
Have also used it to bleed brakes by hooking it to the bleeders under vacuum, works well and very easy to do. It is a breeze for aft drain and fills.

I got tired of pumping it manually- slow and lots of pumping, so I removed the vacuum relief valve and put a hose there to a vacuum pump. What a difference, I used to rent a pump from Autozone but got tired of that. I bought the vacuum pump from HF that hooks to my air compressor and it works great for this.

 

[racer12306]

Why American car companies do not install a drain plug is beyond me.

Preach that.

Very fortunate my Ram does have drains on all three boxes, but the Wrangler does not, just the TC. Fortunately, it looks like the front and rear on the Wrangler have reusable gaskets instead of silicone.



[FlameSuitOn]

Any differential, that doesn't have a drain plug, and is serviced at a quickie lube will have had the fluid sucked out with a vacuum pump. In my several years of working at JLube in the mid 2000s they had a suction hose on every bay, flip a valve and you can almost change a differential before the engine is done draining.

 

[D60]

I think drain plugs could be added to most axles, but tapping NPT is kind of a PITA.

With the invention of reusable gaskets I don't necessarily fault automakers for not including plugs. I'm so over RTV, though. It takes too long to clean everything up then apply carefully then wait for it to cure -- or spend $15 on the Cheez Whiz Right Stuff.

I try to put a Lube Locker, Lube Locker copy, or OEM reusable gasket on every diff cover I pull. The next tech will thank me

 

[JeffKeryk]

I think drain plugs could be added to most axles, but tapping NPT is kind of a PITA.

With the invention of reusable gaskets I don't necessarily fault automakers for not including plugs. I'm so over RTV, though. It takes too long to clean everything up then apply carefully then wait for it to cure -- or spend $15 on the Cheez Whiz Right Stuff.

I try to put a Lube Locker, Lube Locker copy, or OEM reusable gasket on every diff cover I pull. The next tech will thank me

My old Tundra services are a snap. I even raise the left side to get a more complete drain. Hard to do without a drain plug.

 

[TheLastWord]

This is correct. Water and brake fluid are miscible fluids and are subject to the laws of diffusion. Every time you apply the brake, it aids diffusion.

Well not exactly. It may not circulate like other fluids, but it also does migrate. Another law of chemistry to explore.

 

[TheLastWord]

duplicate

 

[D60]

My old Tundra services are a snap. I even raise the left side to get a more complete drain. Hard to do without a drain plug.

ASSuming drop-in third, yes you are CORRECT!!!!!!!!!!!!