Where to lookup/find oem parts?

Pete store dot com for oem, parts truck pro or fleet pride or any local truck parts store like Napa o Riley depending on whereabouts you live northern Indiana has power brakes and springs store,

 

Peterbilt was more like an assembler than a manufacturer. Most things on the truck will be made by another company. If you can identify who made the original part it makes searching easier. Some things like electrical parts will be the same across multiple trucks and manufacturers but with different connectors. You can buy the generic part and put the connectors on to match what you have. The wiper switch and turn signal stalk are like that. The double rectangle headlights were used by several manufacturers. I bought new springs for mine from the local Blue Bird bus dealer and the adjusting screws are Dorman from Autozone or Rock Auto

Fan clutch, block heater, dipstick - specific to your engine (somewhat), probably made by a third company
Try Horton for the fan clutch: https://catalog.hortonww.com/index.html
Trailer air supply and locking diff toggle
Velvac - https://www.velvac.com/sites/default/files/resource-files/04-air_0.pdf
Tramec Sloan - https://tramecsloan.com/wp-content/uploads/2018/09/TS-Full-Line-Catalog.pdf

I have the build sheet for my truck but it doesn't do as much good as it used to. Peterbilt changed a bunch of part numbers a while ago. Even if I go into the dealership with a part number they have a hard time finding what I need. Not much interest from them in keeping a 30 year old truck on the road

 

Yea, no. Ain't no money in that!

I replaced mine a few years ago. Fleetpride actually had the best price. It wasn't made by Horton but I can't remember where it came from. If you have the Horton part number you might be able to find a cross from another brand

That does sound high. There will probably be a part number on the valve body that you can look up. You can also just replace the knob and spool. Maybe even just the orings on the spool

What year is your truck and what engine does it have?

 

Pretty sure this was the company that made my current fan clutch:

https://www.fanclutch.com/PicsDocs/Kit-Masters-Catalog-2015.pdf

 

I'm not familiar with the cat fan clutch. On my cummins it's pretty easy to take the snap ring off the back side and pull everything apart. I've got a toolbox full of various pullers and can usually find something that works

The least expensive way would be to grind the welds, take it apart, and track down the parts. The kit may or may not cost a lot more than the individual parts. Bearings will have the size stamped on the side of the race. They should be easy to track down. Some bearings may seem special but aren't. The bearing in my water pump pulley is a bit odd since it only has a seal on the back side. The front is open and you're supposed to pack the inside of the pulley with grease before pushing the bearing in. in stead of ordering the bearing with only one seal I ordered the cheaper standard pulley, then pried the seal off one side and installed it. Same end result, cheaper part

All that takes time. You just have to weigh out if it's worth it to take that time or not. My truck sits on job sites for a month of two so I don't have to drive it to make a living

For the air valve: If you have enough air line, sometimes all you need to do it pull it out, cut some of the end off, and reinstall it. Just gives a clean section of hose for the connector to seal to. Besides that I'm not sure what parts can be replaced on that valve individually. My truck is an '89 and has three individual valves for trailer emergency, system park, and charge trailer

 

IMO, just buy a new hub. The amount of dicking around trying to save $200 isn't worth it IMO.