L3800 50 hour service

teg · Dec 31, 2011

Tibbits said:
...thanks to this site , changing the filter without changing fluid was clean...due to the 'shop vac' method with a wife...

Just a thought about the shop vac method... could that suck metal back into the system vs. losing a quart/gallon just quickly swapping filters???

KYDan · Dec 31, 2011

teg said:
Just a thought about the shop vac method... could that suck metal back into the system vs. losing a quart/gallon just quickly swapping filters???

I don't know I have never tried it. The 50 hour services are the only times I have changed the filter without draining the system and replacing the fluid as well. I did notice that the fluid at the 50 hour service appeared clean a fresh.

suzy · Dec 31, 2011

My m7040 (purchased this summer) manual called for 50 hour oil and hydraulic/transmission changes. There were spiral filings left over from manufacturing on the magnetic filters, so probably good to change the fluid too. Trying to see if I can recycle the fluid for wood siding stain or something...

redsox1 · Dec 31, 2011

I didn't try the vac method, I didn't understand how the vac running at the fill spout could actually keep the fluid from flowing out when I removed the filter (still don't for that matter). All I could picture was my shop vac somehow sucking in gallons of hyd. fluid so I went the messy route instead.

ritschner · Jan 1, 2012

The shop vac method works! It creates enough vacuum to keep the fairly viscous hydraulic fluid (compare to water or fuel) from flowing out of the filter assembly. You have to remember that the filter assembly does not open directly to the transmission case, but travels through some lines and assemblies. It is sort of like sucking water up and holding it in a straw before you blew it on your siblings as a child. Also the fluid level is low enough that it is nowhere the intake of the shopvac.

k0ua · Jan 1, 2012

ritschner said:
The shop vac method works! It creates enough vacuum to keep the fairly viscous hydraulic fluid (compare to water or fuel) from flowing out of the filter assembly. You have to remember that the filter assembly does not open directly to the transmission case, but travels through some lines and assemblies. It is sort of like sucking water up and holding it in a straw before you blew it on your siblings as a child. Also the fluid level is low enough that it is nowhere the intake of the shopvac.

Yes it does work, but there will be a little fluid sucked up, I think it is due to the air bubbles being sucked in at the filter location and traveling thru the fluid and bursting at the top of the fluid and then a little of the fluid (spray) becoming airborne and being sucked up in to the vacuum. We are talking about a coating of fluid here not an appreciable amount. One other method I was told would work, but haven't tried it was to park parallel on a steep slope with the filter uphill. The idea is the fluid will run away from the filter opening.

James K0UA

redsox1 · Jan 1, 2012

Very good info fellas, thanks I will definitely give it a try next time the opportunity presents. It makes sense after the explanation and thinking it over a bit.

Rail Dawg · Mar 1, 2012

Quick question guys:

My L3800 HST manual says there is a transmission oil filter and a hydraulic oil filter.

Is that the case?

Thanks!

redsox1 · Mar 1, 2012

Yes, there are a total of three filters to change at the 50 hour mark (including the engine oli filter). They all look like regular car oil filters but are slightly different sizes.

Rail Dawg · Mar 1, 2012

redsox1 said:
Yes, there are a total of three filters to change at the 50 hour mark (including the engine oli filter). They all look like regular car oil filters but are slightly different sizes.

Thanks and thanks for posting what you did. Very helpful.

Chuck