Need advice for a grease pit

Or service pit for doing oil changes and service work on a truck. I'm remodeling part of the cattle shed so it will eventually be a service shop mainly for a truck but the tire changer will be in there too, and who knows whatever else. Anyway, the shop will be 40 feet long and the semi tractor is close to 30. Some of the floor is still dirt so I'll be pouring cement next summer so now's the time to come up with plans for digging in a pit for the truck to straddle. How deep should it be? My son is 6'3 I'm 6'2 so we're thinking 5'6" depth. Neither one of us can work stooped over and we figure if we need to reach up into the frame far we can use a low step stool. How wide should it be?

We were brainstorming tonight and I came up with an idea of having a track recessed in the sidewalls for a cart to run on to hold the oil drain pan, tools, or whatever. The rails should be heavy enough to hold a truck transmission, so I'm thinking 2000 lb. Air and electricity will be available in the pit. I'd like to have lights shining up from below but I can see problems with that idea unless you guys have a good suggestion.

How long is the average pit for truck service? This is not a rush job and it will not turn into one. If I do this myself I can add a lot of bells and whistles economically. The building is located on gravelly, rocky soil, moderately high profile and my assumption is there will be no problem with ground water.

What should I NOT do? Lots of questions but I'm going to run this through my mind all winter so I can hopefully have my act together next spring or summer when I can hopefully get it done. Jim

Pits should have ventilation to prevent the accumulation of explosive vapors. The classic disaster is to puncture a gas tank and drop the trouble light into the mix. The bulb shatters and there is no way out quick.

No pits anymore.
Those four point chassis lifts rule. Much more room under and around to service the vehicle. Getting cheaper to purchase too.
As previously stated, a vast improvement in safety.

Never thought of that. I suppose LP gas vapors would be in the same class. Jim

I've seen four post lifts for trucks and that would definitely be my first choice if I had about $150,000 laying around for a new shop building with a 20 or 25 foot ceiling. But that's not gonna happen. A four post lift for servicing the cars and pickups did enter my mind when I thought about what I had available for ceiling height. Jim

Your gonna had a hard time when it comes time to insure it.

If there is any way to put a drain in the bottom I would. I would also pour a set of stairs on one end to get in and out of the pit. Also I would never use a trouble light in a pit, use the rechargable LED hand held lights. No cord to get tangled up in. JMO

Bob

I would not put in concrete steps but rather metal steps which could be moved or replaced if desired. The nicest pit I saw extended under where the tires ran, that is the exposed hole might have been about four feet wide, but down inside it was about three feet wider. The other thing about that pit is that it was deep enough to walk upright under the ledges on each side, but there was a walkway in the center which was higher so you could reach up to whatever you are working on. As which the steps, this walkway is not fastened down and could be lifted out and changed if it proved unsatisfactory. Somebody mentioned fumes. Maybe the pit needs to have an exhaust fan in it.

The vapor in the pit is definitely a issue, but certainly one that can be delt with. Someone mentioned an exhaust fan. That's an excellent idea. I was going to suggest covering the pit with 2" oak planks, about 8" wide, on a shelf around the perimeter of the pit so the planks are flush with the floor. That way, you use a transmission jack over the pit, while standing in the pit. While owning a 12000# lift, I'd cast a vote for the pit, mainly because when you're not using it, it disappears. I think the only real advantage a lift has over a pit is the fact that during several trips to the toolbox, you have only to walk under the vehicle, as opposed to going up and down a flight of stairs.

Find a couple of truck shops and take a tape measure with you. Most truck stops with a shop will have a pit(evening shift will have fewer bosses around to say no)buy sodas for the shift. Lincoln Equipment will have lots of ideas for tools in the pit.(oil drains,jack pans,etc.

A couple years back a friend of mine put a pit in his truck shop. Although I don’t remember the exact dimensions a would guess it to be about 3 1/2 feet wide, just slightly narrower than the inside dimensions between duals frame to frame. For length it’s about 14 ft. long, most of his trucks are R model Mack’s and if I remember correctly you can park completely over it so you don’t step into it while working on a lone tractor. He had a precast company build and deliver it; they put a sump pump recess in on one end in case it ever took on water. They set it on sand about 8” below concrete grade with a slight slope towards the sump, and poured the floor over the top edge of the pit. Before pouring the surrounding floor he sunk a pipe or a piece of concrete tube vertically outside the box for an external sump hole, after the floor was finished he fashioned a steel cover for the sump. I think all of his air and electric comes through a 2-3 " pvc pipe under the floor from the nearby exterior wall. I thought it was a pretty good design.

Alot of good ideas so far. You talk about using a step stool to get additional height. Instead of that why not form a ledge a couple of inches wide along each side at what you'd consider a proper height. That way you can get a couple o pieces of metal decking, some oak boards, or whaever and make an actual work platform that will be much easier and safer to work off of than a step stool.

I built one for the local garage 30 years ago,blocked out a two inch deep by two and a half inch or so wide lip around the top for cover boards,also had a sump pit with sloping floor.The backhoe dug it square enough that I only had to form up the inside,forget how I supported it,poured the floor and walls at the same time. It fills up to almost the top with water in the winter.It hardly gets used anymore.

If the pit can stay open a nice idea is to cast a piece of flat bar with a piece of steel tubing welded to the top edge and sticking up about 3 inches above the floor as a tyre guide,Taper this off at the approach end.Another good idea is to slope your side wall inways from the top and down just about 8 inches from the top edge.You can leave a flat 'shelf ' here for setting tools,but you could mount fluorescent lights along each side for light.If done right this ledge would also support a rolling frame that would lower a tranny with an appropriate jack mounted on the frame. Again if thought out right you could lower the tranny,then roll the frame to the end of the pit and lift the tranny off for repairs.
Keep on thinking and hope this helps....Sam

I would go to a truck repair p;lace and look at the one they use and ask if improvements could be made if they did it again.

I built our company's pit when I did the new shop about 12 years ago. Don't remember the depth, but I know it's deep enough to walk through comfortably and they use small stepladders for work when necessary.

A big plus to that pit was installing rough-ins for lighting. They lined a recessed portion of the walls with fluorescent, feels less like a cave when it's lit up nice and bright.

You might want to check state/local law on them and insurance. They went out around here and some people had to remove them.

This is a good thread. I like hoists, but those fast-change oil places all use pits. There's one near me, and I think I'll go have a look at their pit. It seems very efficient. On our four post hoist there are two rolling hydraulic jacks that lift the front or back of the vehicle. And with good lighting, electric and air outlets, I can see a pit being more efficient... I'll have to give that some thought for my next shop.

Thanks for the thread.

Make sure theres a good way of escape

jimmy

What is the rafter height?
The wider the better,so the front wheels are the limit.The inside duals don't have to support weight.
An electric fan is going to be an ignition source even pulling air instead of pushing air. Unless it's a class I or class II explosion proof fan.
A pit is going to cost thousands when all expenses are totaled up. A HD floor jack and some oak blocks are more economical.

Thanks for the ideas, even the negative ones.

I'll have a chat with my insurance man. This is on the farm, not commercial. If that makes a difference or not, I don't know. If my son's trucking friends want to come use it I can maybe use "insurance purposes" as an excuse to turn them away. Jim

A construction company I worked for years ago had a project to build a lube pit at Fort Carson Colorado. It involved a LOT of concrete forming, and adding the tracks etc for the oil drain pan etc, along with the plumbing, electrical, and ventilation, made it incredibly complex to build. That pit was really expensive. I would really reccommend going with a lift instead of a pit.

Fixerupper I started to help build 1 many years ago, the man would not listen to advice. Would not put in a drain even though he could have. Didnot use enough form material-1/2" plywood-with little inside sidewall bracing. No electrical plugs, which turned out to be good. The sidewalls bulged in so far they would have destroyed any wireing and it filled up with water one night when it rained 7inches. I left before the cement was pored. Think it out-most are as asset to the operations that have them.

Mine is made with 8 inch wide "Poured Walls" with
1 foot wide "Footings". I left a sand bottom, but there is room on the inside of the walls, on
top of the footings, to put 2 x 6's across to
stand on, for heighth.I'm 5'10, so my depth is
6 feet from the top of the shop floor, down to
the top of the footings. Width is 4 feet, length
is 15 feet. Access is by steps at the shop door
end. I have a "Ground fault outlet at each end,
and Air quick dissconnects at each end, for air
tools. I left a 4 inch wide ledge on each side,
three inch's below floor level, and have cut
2 x 6's to fit in all the way, so it has a completely covered floor when not in use.
In winter, in Wisconsin we get several months of
freezing weather,(actually, 3 or 4 months) and
2 to 3 weeks of 30 below zero weather. We store
bulbs and root vegetables in the pit, and they
never freeze there, even when there's no heat in
the shop. We call it our "Root cellar".

Here's a few pics of the one I put in my shop. I considered a lift , but didn't want it taking up valuable real estate when not in use.

Poured floor, block walls filled with concrete and rebar, 1/4" plate steel doors. It's 4' x 16' x 5.5' deep. The trusses sit on an angle iron ledge and slide out of the way. This was back in 2000 when 1/4" x 4' x 8' plate was around $75.

I also put a small sump crock in the corner to pump it out when needed. With all the rain as of late there was about an inch of water in there today.

I can't really take credit for the design. I just copied the one my Dad built with a couple of my uncle's help and doubled the length.

Those pits are dangerous. Check your local/state laws to see if it is even legal to put one in, I know in some areas they have been banned in commercial shops. Also check with your insurance companies, I have heard of companies canceling building and content insurance due to a pit being put in (high risk of fire/explosions from built up-vapours, among other dangers).