Who are the experts on the Air compressor

[shawnspeak]

No instructions in the kit here

 

[GeneralDisorder]

No instructions in the kit here

All of the Haldex RNT26 kits I have bought came with an instruction sheet.

 

[shawnspeak]

If someone could take a picture of the sheet and post it here, both I and the next unfortunate soul without one would greatly appreciate it. Otherwise, fingers crossed for responses from Haldex and/or the vendor I bought the kit from.

 

[Aviator4x4]

If someone could take a picture of the sheet and post it here, both I and the next unfortunate soul without one would greatly appreciate it. Otherwise, fingers crossed for responses from Haldex and/or the vendor I bought the kit from.

Hopefully you got an answer, but found this in the sealed white envelope with all the gaskets

 

[MGVFD]

I suspect you will still find leakage elsewhere. There is an output check valve on the air dryer, so once the air is pumped past that, there should be no going back to the compressor... If it is happening while driving, i would first inspect the park air lines, anti-compound valve and spring chambers. a park chamber leak would pass out thru the cage bolt holes. Depending on your year, you may also have a remote control valve inboard of the pri-sec tanks that disconnects air to the air/hydraulic pump when park air is applied.

Chock the wheels release the park brakes, a bad 2way could send park air out the front red glad-hand vent. Are the rear glad-hands capped/sealed? Fronts are vented, rears must be sealed...

Sorry for my ignorance. Where is this two way valve located? We have air coming out of our Red glad hand on the A1. TY

 

[GeneralDisorder]

Sorry for my ignorance. Where is this two way valve located? We have air coming out of our Red glad hand on the A1. TY

There's three two way valves behind the driver's side step curtain. Look UP behind the step with the washer bottle.

There is another one-way check valve right behind the glad hands.

And there's a couple more one-way checks behind the service and wet tanks.

Replace them ALL. They are cheap off-the-shelf Haldex parts that you can order at NAPA.

 

[Piatheem]

Where are you sourcing compressors/heads nowadays?

 

[GeneralDisorder]

Where are you sourcing compressors/heads nowadays?

Mine was worse - punched a hole in a piston.

Ebay, surplus channels and surplus truck/parts dealers, Napa, FleetPride, etc. I got a good used compressor for $160 on ebay and rebuilt the head and then rebuilt my original head to carry for a spare.

It's all off-the-shelf Haldex parts.

These guys are an awesome resource also if you don't want to do the work yourself:

Brake Systems Inc. - Manufacturers of Blue Ox Exhaust Brakes

BRAKE SYSTEMS INC. has 40 years of experience Manufacturing, Remanufacturing and Distributing quality brake components. We are ISO 9001:2008 certified. We specialize in Brake and Throttle Components, Electronic Throttle Controls, Exhaust Brakes, Blue Ox Exhaust Brakes, Air Shifters, Air...

www.brakesystemsinc.com

 

[Piatheem]

I am interested in your used compressor, can you send me a link to eBay listing?

 

[GeneralDisorder]

I am interested in your used compressor, can you send me a link to eBay listing?

No...... I *bought* one for $160 (free shipping!) off ebay! You have to be watching for those deals.....

Here's one - this seller usually accepts make offers I've noticed:

NOS/Remfg Midland Vehicle Air Compressor for MRAP, 2530-01-361-5075 a | eBay

Surplus, NOS or reman, compressor regulator/bracket broken off, light surface from damp storage, Scuffs, AS-IS.

www.ebay.com

 

[Piatheem]

Mine was worse - punched a hole in a piston.

Ebay, surplus channels and surplus truck/parts dealers, Napa, FleetPride, etc. I got a good used compressor for $160 on ebay and rebuilt the head and then rebuilt my original head to carry for a spare.

It's all off-the-shelf Haldex parts.

These guys are an awesome resource also if you don't want to do the work yourself:

Brake Systems Inc. - Manufacturers of Blue Ox Exhaust Brakes

BRAKE SYSTEMS INC. has 40 years of experience Manufacturing, Remanufacturing and Distributing quality brake components. We are ISO 9001:2008 certified. We specialize in Brake and Throttle Components, Electronic Throttle Controls, Exhaust Brakes, Blue Ox Exhaust Brakes, Air Shifters, Air...

www.brakesystemsinc.com

My piston seem to have survived.

 

[Plasa]

Thank you all, you saved me from a bigger damage!
My LMTV have 50000 miles, air system without big leaks. But anyway I discovered a broken spring:

I doubt the the new springs will survive forever, so my question is: after how many miles it should be rebuild again?

Christian

 

[Piatheem]

Is there a permanent fix for those springs? The parts of the broken spring travelled all the way to the air dryer. I am building an expedition truck and want to make sure it wont happen again.

 

[Plasa]

After 8 years owning an LMTV I can confirm that nothing on this tucks will be permanent, except the constant maintenance tasks.
If you think you found all the gremlins I can bet there are a lot more waiting for you

What should be intresting is what haldex says about preventive rebuild of this compressor. I think it's a matter of age and not how long the compressor run.

Christian

Is there a permanent fix for those springs? The parts of the broken spring travelled all the way to the air dryer. I am building an expedition truck and want to make sure it wont happen again.

 

[Ronmar]

some of the failures may also be related to the high RPM they must endure at highway speed with the 7.8:1 axle ratio... The only other people who run these engines approaching that high an RPM are the marine users and they don't have air compressors fitted...


You can still see the marks from the cylinder hone in that last pic... After 50K?

 

[Plasa]

Yes, they are pretty clear, I was not expecting that. Did a test after I rebuild the head, I did not hear any diffrence when running in idle, it can be that loads a little faster than before.

Christian

some of the failures may also be related to the high RPM they must endure at highway speed with the 7.8:1 axle ratio... The only people who run these close to those RPM are the marine users and they don't have air compressors fitted...


You can still see the marks from the cylinder hone in that last pic... After 50K?

 

[Piatheem]

I continue tracking down why the compressor cycles every 2-3 minutes, instead of expected 15m. I have fixed multiple leaks, now if I connect the truck to the shop compressor, put 120 psi in the system, it holds the pressure well. It's hours before the pressure drops to 110 psi. But, if a compressor unload event happens, I start loosing pressure very fast. I disconnected the governor and connected the shop compressor with the pressure gauge to the unload inlet. Looks like it's not holding air at all. Is my new compressor head trash?

See the video:

IMG_1767.MOV

drive.google.com

 

[aw113sgte]

I continue tracking down why the compressor cycles every 2-3 minutes, instead of expected 15m. I have fixed multiple leaks, now if I connect the truck to the shop compressor, put 120 psi in the system, it holds the pressure well. It's hours before the pressure drops to 110 psi. But, if a compressor unload event happens, I start loosing pressure very fast. I disconnected the governor and connected the shop compressor with the pressure gauge to the unload inlet. Looks like it's not holding air at all. Is my new compressor head trash?

See the video:

IMG_1767.MOV

drive.google.com

Have you rebuilt your air drier? If it purges and doesn't close completely that could be the leak.

 

[Ronmar]

Connect pressure to the purge port on the dryer.

The air exits the dryer thru a check valve to the wet tank. If that check were leaking your shop air test should show that. The system feeds air from the wet tank to the governor the governor monitors this air to control its cycling, and also feeds this air back to the dryer purge port When it unloads at 125PSI.

Not sure if the governor will unload without the compressor/engine running, but I suspect it probably will, but you need to apply enough air pressure to the system to exceed its cutoff point, which should be ~125 PSI. You would know its happening as it sends air back on that purge line to the dryer purge port.

with the system at 120, I suspect you could disconnect the dryer purge line, apply 120PSI to the dryer purge port and look for leaks, and also apply 120 PSi to that purge line back toward the governor and look for leaks along that line.

a leak on that circuit would explain your symptoms, static system holds pressure well. When running, system fills, governor unloads, dryer purges and the leak quickly drops wet tank pressure to the cut-in point, leak stops when the purge line is depressurized by the governor, and the compressor quickly refills the system only to re-apply the leak and start the 2min egg timer all over again…

Arn’t air systems cool

 

[Piatheem]

Have you rebuilt your air drier? If it purges and doesn't close completely that could be the leak.

I bypassed the air dryer, and supplied pressure to the unload port on the compressor. That’s a good theory though, I have checked the exhaust valve at the air dryer and it’s not leaking.