UPDATE: Diesel to flush transmission???

[whitetiger]

Flushing with diesel fuel will not hurt your transmission or rear end but can damage your hydraulic pump. If you start the engine with diesel fuel in the hydraulic system, it will be pumped through the entire system. Now, how do you flush the diesel fuel back out??
You can flush and change the hydraulic oil numerous times, each time diluting the diesel to a lesser percentage. After several flush/oil changes, you will still have some diesel in the hydraulic system.

Does anyone top off their hydraulic system with diesel when it is low? Of course not. I wonder why if diesel is so much cheaper than hydraulic fluid?
If diesel fuel will not damage the hydraulic system, why mess with hydraulic fluid at all?

Do you see where this is going? Why not just flush with hydraulic oil and be done with it?

 

[SDT]

Flushing with diesel fuel will not hurt your transmission or rear end but can damage your hydraulic pump. If you start the engine with diesel fuel in the hydraulic system, it will be pumped through the entire system. Now, how do you flush the diesel fuel back out??
You can flush and change the hydraulic oil numerous times, each time diluting the diesel to a lesser percentage. After several flush/oil changes, you will still have some diesel in the hydraulic system.

Does anyone top off their hydraulic system with diesel when it is low? Of course not. I wonder why if diesel is so much cheaper than hydraulic fluid?
If diesel fuel will not damage the hydraulic system, why mess with hydraulic fluid at all?

Do you see where this is going? Why not just flush with hydraulic oil and be done with it?

Again, it will be interesting to learn why and how diesel oil, which is a lubricant, will damage one's hydraulic pump, PS, etc.

SDT

 

[nocash247]

Again, it will be interesting to learn why and how diesel oil, which is a lubricant, will damage one's hydraulic pump, PS, etc.

SDT

The diesel won't damage the pump itself. It will damage the seals in it. It won't cause any damage to the metal gear but it is still not preferred to avoid possibly rebuilding the pump to replace all the seals.

 

[SDT]

The diesel won't damage the pump itself. It will damage the seals in it. It won't cause any damage to the metal gear but it is still not preferred to avoid possibly rebuilding the pump to replace all the seals.

It will be interersting to learn how diesel oil will damage the seals in PS and/or hydraulic pumps.

SDT

 

[NHSleddog]

It will be interersting to learn how diesel oil will damage the seals in PS and/or hydraulic pumps.

SDT

Agreed.

And as an aside, EVERY hydraulic cleaning/conditioning fluid all have one thing in common, none of them are hydraulic oil.

 

[nocash247]

It will be interersting to learn how diesel oil will damage the seals in PS and/or hydraulic pumps.

SDT

I imagine it has to do with the detergent additives in the fuel? I know I've been told by a few technicians that it isn't a good idea. I'm interested on why you would try it. What about diesel gets rid of water? If the tractor had been sitting and the fluid was a congealed mess I'd say it would work like a charm but multiple fluid changes are still my opinion on the best course of action to get rid of water.

 

[SDT]

I imagine it has to do with the detergent additives in the fuel? I know I've been told by a few technicians that it isn't a good idea. I'm interested on why you would try it. What about diesel gets rid of water? If the tractor had been sitting and the fluid was a congealed mess I'd say it would work like a charm but multiple fluid changes are still my opinion on the best course of action to get rid of water.

I would try it because I've done it multiple times in the past without issues. Tractors have all had hydraulic pumps and some had PS.

I have no reason to believe that the seals in hydraulic pumps, PS systems, etc., are made of synthetic materials different than the materials used in injection pumps, transmissions, etc.

What about hydraulic oil gets rid of water?

SDT

 

[jigglypuff]

I made an update to original post which is also copied below. Any comments welcome! Thanks again for all the great advice!


Update: so after a lot of consideration and enjoying the conversation on this forum, I decided to do a diesel flush.

I appreciate all the advice and my decision was informed by, and considered, all the advice. In the end my old school uncle, who has done diesel transmission flushes for longer than I’ve been alive, convinced me.

My procedure: 1. Drain tranny overnight, clean filter screen. 2. Replace screen and all plugs, fill tranny with three gallons of diesel. 3. Run engine for three minutes (no play on hitch or loader). 4. Drain diesel overnight, clean screen. 5. Replace plugs, screen, fill to specs with hydraulic oil. 6. Back in business

I admit that I was skeptical at first and remained so after reading reply’s to my original thread, and was leaning toward a straight hydraulic oil flush. In the end I trusted my uncles judgement.

After running the clean diesel for three minutes, it drained out a milky colored thicker consistency that told me it flushed out a high percentage of the water contaminated hydro fluid.

The hydraulics are back in good working order and everything seems to be working right. Any long term affects to the pump or it’s seals will be reported here, but nothing noticeably out of wack after running a tiller on the back end for a couple hours.

This might not have been the “right” way to flush a transmission, but it was a way that worked for me. I guess you don’t always have to follow the textbook when it comes to certain things.

Any comments or questions welcome

 

[SidecarFlip]

My only comment is... Been doing it for years in high mileage engines with no issue. Should be no different in a transmission.

Myself, I kind of prefer Nano-Borate because it has an extremely active rate of cleansing power but it is very expensive too.

 

[Orange man]

Not sure how the brake discs will like the diesel, Maybe not enough diesel to hurt them.

 

[jasowiii]

I have a sludge that is not dissolved by hydraulic fluid. It is the consistency of grease. this is my brake assembly housing but I am confident that this sludge is present in the transmission. The brake discs failed and pieces of brake fiber are mixed in w this sludge.
If not diesel are there other additives/solvents that are ok to use?

i

 

[DaveFromMi]

I have used Seafoam to dissolve gunk in gas engine crankcases. Rule of thumbs 1) Ratio on no more than 1 part Seafoam, 4 parts old oil. 2) careful not to overfill.
Before adding, get oil warm by running engine. Drain out some oil, see above ratio, refill with Seafoam. Run engine about 5 minutes. Drain crankcase and refill with proper oil and amount.

I'm thinking similar procedure with hydro fluid, maybe not as much Seafoam.

 

[jasowiii]

Sorry forgot to add the model is an M4500. 1980 ish. Plenty of hours but sat for probably 5 years. Was on a working orchard.
Brake cleaner dissolves the sludge but I have no intention of running it through the pump...