What air compressor?

[bkvail]

My husband and I have been building a '36 diamond t for a couple years and we are hoping to get it to where it is somewhat driveable by the end of the summer..... in order to do that, we need to figure out the suspension and brake system......

The truck is a dually (GM 12 bolt), powered by a cummins 6BT with a 5-speed. We plan to use air over hydraulic for the brakes (front discs are from the front clip from a '91 Dodge), rear has drums. And, we also have air for the rear suspension (plan to upgrade front to air at a later date).

So, we are at the point now that we need to gather more parts - starting with a compressor. I am usually the parts gatherer because hubby works long hours - so I am asking here because I have NO CLUE what we need! I looked on a couple websites and that didn't answer any of my questions, LOL.

What size/brand/etc. would you suggest for a compressor for air/hydraulic brakes PLUS air suspension? I don't want to say cost is no issue, but we do want to get what we need and not have to upgrade later.

So far, all we have is one air tank, but we do plan to get another. The one we have is from a Peterbilt log truck - it's not huge, but I think it's plenty sufficient for the suspension - we will get another matching/similar one for the air part of the brakes.

Karin

 

[Yankee Transplant]

I have no clue on this either but I do know you need to be sure you have the bolt holes for the type of compressor you get .. that may be a helpful bit of imfo on which is available for your engine .. just my 2 cents

 

[kenny c]

Are you looking for a compressor that is engine driven or a 12 volt one like that is used for an air ride system? you could also use a hydro boost for the brakes

 

[zzrodder]

I've seen A/C compressors used as an air compressor - this could be a low cost alternative and supply all the air you'd ever need. I know I've seen a thread here dealing with A/C compressor use, which one are best, tricks to using them, etc. but can't recall which category it was under..... maybe someone else remembers it ? [S

 

[Bamamav]

Some of the old 50's and early 60's trucks with gas engines used a V belt drive air compressor. If there is an older truck wrecking yard near you, that might be a good place to start looking. They would be on the 1.5 ton and larger gas powered trucks, like old single axle dumps or single axle tractors. You might even be able to get a new one from a truck supply place that deals in that size trucks, think city or county dump trucks for example.

 

[sneakysnake]

I recommend this one for a 12v. If you have the room the AC compressor conversion. is a low buck way to have all the air you need as long as the motor is running.

 

[bkvail]

oops, forgot to say there is not enough room for an A/C compressor (very narrow front grill) - we have a place to put the compressor that we can bolt it down (we are looking for a 12v)

 

[Sam_Fear]

I don't know much about Cummins, but doesn't the 6bt have a place to hook up a gear drive air pump? That would be the way to go. 12v is way slower and noisier than a engine driven pump.

 

[21willys]

The 91 dodge hydro brake system should be fine as is. Why complicate it by trying to add air over hydro to the system? Am I missing something there?


Just keep it simple. Way less headaches later down the road.

 

[bkvail]

The 91 dodge hydro brake system should be fine as is. Why complicate it by trying to add air over hydro to the system? Am I missing something there?


Just keep it simple. Way less headaches later down the road.

We are making it a ''mini'' big-truck. My husband is a log truck driver/mechanic for 30 years.

 

[bkvail]

I don't know much about Cummins, but doesn't the 6bt have a place to hook up a gear drive air pump? That would be the way to go. 12v is way slower and noisier than a engine driven pump.

hmmm, I am not sure! Will ask our cummins mechanic friend - hadn't considered that. I know it has vaccum for the original vaccum assist brake system.....

 

[jmlcolorado]

All cummins have the ability to use the gear driven compressors. They mount on the drivers side of the block, where the power steering pump is. And the power steering pump is then bolted to the compressor so you can have both.
I've seen them very recently on flea bay for a few hundred.
I'm not familiar with air over hydraulic brakes, but I would be apprehensive about using an electric setup in a braking system.

Edit: here's one, my pricing appears to be skewed. Few hundred plus core, all the way up to $700ish.
http://www.ebay.com/itm/Cummins-Air...296-/181738364055?hash=item2a50735c97&vxp=mtr

 

[bkvail]

OK, apparently my husband DID know that the cummins can run a gear driven compressor - he just didn't think it was going to fit (there is not a lot of extra room under the hood). So, I am going to do some more research on the gear driven one, and see if we can possibly make one fit. THANK YOU!

EDIT TO ADD: looks like the gear driven air compressor would go in place of the power steering pump.... we kinda need the power steering though!

 

[Bamamav]

The power steering pump should mount to the back of the air compressor and be driven by it. If you have a belt driven pump now, you would need the one that bolts to the air compressor.

 

[21willys]

What are the plans for the rest of the system to make it air over?

 

[bkvail]

aha! I didn't realize the power steering could go behind it! I am hoping that the local cummins guy will have one we can at least measure before we purchase - it will be close if the hood will clear it, so we will have to take careful measurements!

As far as the rest of the system for the air/hydaulic - we saw the system on ''Gearz'' - https://www.staceydavid.com/projects/19427/heavy-metal-2291
(the e-brake will be separate as to not blow out the wheel cylinders - we want to do a push/pull valve on the dash, but I think it will activate a driveline brake instead. We will see when we get there!)

We didn't have room on the firewall for the original Dodge master cylinder and it's HUGE brake booster. We barely had room for the clutch assembly since the firewall is so much narrower.