Geoff Weeks

https://www.powersystemstoday.com/parts/search/gerhart-machinery-co-lititz-pennsylvania?LocationID=350007704819&SearchType=Start Claims to have 3 N.O.S. but doesn't say how much. From the Pic shown they are Trico's. I would contact Rome about rebuilding yours. Also there might be a Sprague replacement for the Trico.

Air wipers are simple. Rome Truck Parts, is a source for wiper parts. Trico wipers are hard to find replacements for but Sprague motors can often be set right with under $3 in O rings. I don't know what motors you have, do you have a picture?

My Marmon uses an almost identical unit to the Red Dot in my Mack sleeper. From what I remember, the thermostat control on the sleeper wall turns the fan on and off based on temp. The thermostat goes bad and fan doesn't run. As Joey suggests check for power to the fan, if there is power but no fan, then the fan is at fault, if there is no power it could be the fan resistor or the control board.

The O/P'er said he removed the line and checked for that. It is a good first thing to check.

There is a line from the brake service line to the spring brake relay with anti compounding or separate anti compounding valve. If that valve is defective it will pipe air for the spring brakes to the service line to the chambers, the quick release portion of the service relay will be open and will dump the air. When the brakes are pressed the 1st thing that happens is the quick release portion of the service relay closes. Without being there and seeing exactly what is happening, that is my best guess with the info we have now. Inversion valve is another possibility.

May be I am mis understanding here. My understanding is that it is leaking out back on the frame by the brakes, not at the buttons on the dash. A photo of the valve that is leaking would help. As previously stated, there a a few places the service and spring brake systems interact. knowing where the air is coming out will help. It may not be the valve that the air is coming out that is the problem, it may be another valve that is letting spring brake air into the service brake lines.

If it uses a compression nut and "olive", they can stick, sometimes there is no out but cutting. If you have to replace, make sure the old and new are the same length. When the tubes on my cabovers rusted, I replaced with stainless tube. the end that the dipstick tightens in (bell mouth) was just brazed onto the tube, and I transferred to the new stainless. That said my cabover might be different from what you have. A picture would help. The fitting that screws into the block is two parts, you hold the bottom and turn the top hex. Kinda sounds like the bottom is turning with the top, keeping the tube captive.

well pre-121 is a single line system which also plays into it. One res for all brakes. Also tractors weren't required to have front brakes (steer brakes) until sometime in the 80's. Many did, but not all.

The reason it stops, is because before you apply it is venting air that the valve doesn't think should be in that line. It is like when you had you foot on the brake, and let off, all the air doesn't go back up and vent out the foot valve, it would make the brakes very slow to release. so quick release valves or relay valves, when they loose service brake pressure from upstream, vent everything down stream. Once you supply service pressure from the foot valve, the vent is closed and pressure allowed to build in the service line to the chamber. How big is this leak? does it vent all the air and the compressor can't build until you step on the brake? or is it a small leak that stops when the service brake is applied?

Also if this truck has anti-lock brakes there is another whole can of worms.

If I understood, he checked for that.

Also you only mention it happening when the "yellow button" is in, I assume this is a single unit (red button out) when it happens? If you have a trailer there is more that can leak with the red button in.

In North America, there are two other places that the two systems interact. One is the inversion valve and the other the anti compounding. The 1st is a system that if you loose one side of the dual system, uses the spring brakes proportionally applied by the other half of the duel system. It vents spring brake air in relation to brake air on the other system. So there is one place that could leak spring brake air into service air piping. The anti compounding is there to prevent both air service brake and spring brake from being applied at the same time. (prevents too much pressure on the cam and slack adjuster). On both of these it could leak into the other system. If Your leak is a minor one that seams to go away when the service brake is tapped, than I'd look at those two valves If on the other hand, it leaks all the time the spring brakes are off and the service brakes are off, and only goes away when you step on the brake, Then it is likely a relay valve.

Does it use a Push type double disk? I thought I saw a "nose type" front bearing retainer and no upper cross shafting.

If you like what you have, it is ALWAYS cheaper and easier to fix what you have than it is to replace with something else. Driveshaft will be different length almost 100% sure, then there is the mounts and shift. If you have a donor truck that is the same, that you can swap parts off of, it isn't bad, but it is the little stuff that causes the most pain, doing swaps.

The Magnum had big cam oiling, so that is a dead give-a-way. The NTA was different, it was all small cam, and I think the "lunch box" after-cooler. As I say, not a small cam guy so could be wrong. Magnum was externally a Big Cam and used all Big Cam external parts, internally was a small cam. So it would have the Big Cam oil cooler DFC oil pump, and IIRC waterpump/accessory drive pulley, same for aftercooler, all on a small cam block. At this point it could have either in it. CPL 23 and 135 are NTA 420's there are other CPL's as well

does that mean the old content is gone for good? Thanks, btw I was wondering if I had forgot my log in.

Same here

If you have 40 psi the next morning, I wouldn't worry about anything on the protected side (after the primary and secondary tanks) and concentrate on the system from the compressor through the wet tank to the inlet check at the primary and secondary tank. That is where your leak will be. With the drier purging every 20-30 sec it will be a big leak.

I agree, most inspectors don't even know what they are looking at. I've had two that looked at the inside of the spokes and the spacer rings as well as the outside in all my years and inspections. I am not saying that you'll run into that every day. I do know if you use the right parts you'll never have spun wheels or other wheel end problems. What you choose to do is up to you. I know many that will put aluminum "Budds" on short steel studs, and claim there is no problem. I know better and you'll never hear me say you can do it. I'm just trying to explain how it was done from the get -go. What to look for and how to select the right parts.

I ran 10R x 20 radials (Tubetype) and 11r 22.5 tubeless or 295-80 22.5 (same diameter as an 11 but higher load capacity) Can't say I noticed any ride difference between them.

Heelless clamp: Heel type clamp: 4" spacer band: https://www.napaonline.com/en/p/TWDSB4020K?cid=paidsearch_shopping_dcoe_google&campaign=GSC-Towing&campaign_id=8911645606&adgroup_id=106416389246&adtype=pla&gclid=EAIaIQobChMIh83M_92TgAMV3t7jBx0njAqgEAQYAiABEgITJ_D_BwE&gclsrc=aw.ds&

New ones should be available, but not stocked. Special order item. There are two classes of wedges for duals. Heel and heeless clamps. Heeless should never have the heel end touch the spoke, Heel can have a small gap or touch, provided it doesn't touch until the nut is torqued to 80% of final torque. I would be surprised if the side with the narrow spacer has proper duel spacing, and the tires don't "kiss" on the sidewall when loaded. If you measure the flat part of the spoke, from where it starts to taper up in the back, (where the taper starts, don't include the taper) to the end of the cast spoke. If the measurement is: 6" try a 4" spacer band 6 1/4" try a 4 1/4" spacer band If it is less than 6" pay close attention to duel spacing with modern tires. My K-7 has a low GVW of 16500lb still uses a 6" wide (long?) spoke, the same as many modern hubs built for 11x r 22.5 tires. Spacer bands are "sized" by the outside measurement across the band, not inside width. These are the most common combinations. Also there are whole pages of wedges for duals with differing profiles and depths. It isn't a "one size fits all" type of assembly. The wedge must go over the end of the spoke and not be right at the end of the spoke casting when tightened. My 1942 IHC with 8.25x20 tires still takes a 4" band, I doubt that narrow band is correct. If you can find a casting number, or if it is branded (Mack, Gunite etc) see if you can find a part number in a parts book for the correct wedges and spacer.

Here, a DOT cop who knew what he was looking at would fail that. Yes, I have been though a few (very few) inspections where they knew enough and looked for wear, spun rim, and repairs to the assembly. Spacer rings aren't that much money, last time I bought some. I have never had a rim spin on something I assembled, but have seen plenty. I can see making that repair in the field, but not once back where the proper parts are available. Wouldn't pass inspection. In 20" and 22" stuff the spacer band will most likely fall in the 4" to 4 1/2" range (We don't have 24" in this part of the country, so no experience with those). Lighter axles found on smaller trucks may use bands that are smaller than 4", but that limits the tire and rim width you can fit. You say I am "over thinking" things, but you are repairing "spun" wheels? Hum, that lead to the question why are your wheels spinning in the 1st place? I did heavy haul, so carried above the normal weight on axles. Never had a wheel spin, even on hard brake applications. Here we had Webb, Gunite, Erie, and Dayton (and may be more that I am forgetting) making spoke wheels, there were different attaching methods and hardware used, some of which was compatible with other brands and some isn't. Just for example Erie used captive bolts and ball seat nuts, with wedges designed for that. They are not interchangeable with wedges and nuts for for stud based spokes with flat nuts. You CAN fit mis matched parts, just as you CAN fit mis matched lock rings on wheels, but in both cases it can cause a failure, rims may blow the ring out and kill you. Wheel end is just likely to spin and take out the valve, but could snap the stud and cause the loss of the rim/tire. For a while in the 90's (It may still be going on) Canada was having trouble with wheel end coming off trucks and killing people. If they found a wheel end problem they impounded the truck for a week (if I remember correctly) and it couldn't be moved without being repaired, even if repaired the same day, the week had to be "served" before the truck released. I take wheel end seriously, and have never had a problem with spoke wheels. I have had many problems with disk wheels. For a while IHC used the Erie system, my 1942 has them. If the spoke has been worn from loose rims, it is not a one-off time someone didn't install them correctly, it is something that has been going on for a long time. I question the maintenance practice of an operator with that. Parts that are mated and have no movement between them don't wear!

As with anything defective parts need to be replaced, but you don't change spacer bands when changing rims. The spoke determines what is required. If you have rims moving, you have a problem, defective or mis matched parts. If a rim spacer is damaged, replace it with the same width as the original. If you suspect a mis matched parts, then either consult someone who knows what should be or replace the whole assembly. All else fails, you can take the casting number off the spoke hub, from that you can determine the mfg, and contact them for the correct parts for that hub.