• Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!

  • Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.

Mav’s M1088A1 Conversion

Mavcaster

Well-known member
201
422
63
Location
Maryland
Hmmmm

I know that there is a procedure to delete the front towing air connections. And if down wrong....park brake won't release.

Make me wonder if it's a similar problem.

@Ronmar would know.
And that makes sense since those would be applying air to the truck brakes themselves. Hopefully someone here has deleted the 5th wheel connection before and can point me in the right direction. That's the only brake components I have messed with since they were last working so seems like a smoking gun not sure.
 

Third From Texas

Well-known member
2,764
6,492
113
Location
Corpus Christi Texas
And that makes sense since those would be applying air to the truck brakes themselves. Hopefully someone here has deleted the 5th wheel connection before and can point me in the right direction. That's the only brake components I have messed with since they were last working so seems like a smoking gun not sure.

I thought I had saved the front delete instructions, but I can't locate them. Was hoping they might show some insight into your issue.

:(
 

Ronmar

Well-known member
3,791
7,359
113
Location
Port angeles wa
Park brake button popping right back out indicates no air is reaching the park control valve. Or the valve itself has an issue.

It requires air to hold the control in the in/on/air applied/park brakes released position. If all the air bleeds away, the control will pop out under spring pressure and return the control knob to the air off/park brake applied position.
 

Ronmar

Well-known member
3,791
7,359
113
Location
Port angeles wa
Will have to look into the 5th wheel plumbing as I am not specifically familliar with it. It should be basically paralleled off the normal rear gladhand fittings as it serves the same purpose to feed trailer with red and blue(park/emer and service air) brake air. Maybe you didnt cap something and you are venting away all your park air?
 

Mavcaster

Well-known member
201
422
63
Location
Maryland
Will have to look into the 5th wheel plumbing as I am not specifically familliar with it. It should be basically paralleled off the normal rear gladhand fittings as it serves the same purpose to feed trailer with red and blue(park/emer and service air) brake air. Maybe you didnt cap something and you are venting away all your park air?
That’s what I initially thought and maybe off the mark here but tried holding down the button (not sure that matters at all) but that did not drop air pressure at all.
 

chucky

Well-known member
Steel Soldiers Supporter
6,612
18,937
113
Location
TN .
Unless i missed it above doesnt the brake button valves keep popping back out til you have a min of 60 psi in your tanks and wont release the shoes till over 60 psi
 

Ronmar

Well-known member
3,791
7,359
113
Location
Port angeles wa
Park air comes from a 2way checkvalve between primary and secindary air feeding tge pedal. It is located to the left of thebrake pedal. If the service brakes apply air, then air is reaching the 2way. You can loosen tge middle 2way fitting if air comes out then it ismaking it thru the 2way. Next lift the dash panel and find the other end of the supply airline at tge park valve and loosen it. If you get air then air is reaching tge park valve and it most likley has a problem...
 

Mavcaster

Well-known member
201
422
63
Location
Maryland
So one other thing I was thinking was back when the truck wasn’t running I had tried charging the tanks through the emergency front gladhand but it didn’t work so I assumed the check valve was bad. Could I have possibly lodged something in there not allowing it to breath like it’s supposed to? Could that possibly cause the parking brake not to release?
 

Ronmar

Well-known member
3,791
7,359
113
Location
Port angeles wa
So one other thing I was thinking was back when the truck wasn’t running I had tried charging the tanks through the emergency front gladhand but it didn’t work so I assumed the check valve was bad. Could I have possibly lodged something in there not allowing it to breath like it’s supposed to? Could that possibly cause the parking brake not to release?
Applying air at the front red/emer gladhand should fill the tanks, and it should also release the park brake, just like when you tow the vehicle. It should not effect the park valve operation, if it is getting supply air it should stay in when pushed.
 

serpico760

Well-known member
Steel Soldiers Supporter
643
1,623
93
Location
San Diego, CA
.
If it is anything like mine - if you have been getting rain - a drum might be seized to the brake shoes. Seems that several others here have had the same problem. If mine sits around in the rain for more than a week, it requires a "love tap" on the steel part of the brake shoe.

If you have re-plumbed air lines, all bets are off though.
Yeah after just a couple weeks of rain I went to drive mine and it wouldn't move! Went around the truck with a hammer smacking on the brakes giving love taps around the rim of each drum. Got inside and gave it a bit more gas and then a couple popping sounds and then it went. Everything has been fine since then.
 

RRaulston

Well-known member
227
550
93
Location
Sahuarita, Arizona




RIP oil pump…
This is interesting. First off, I watched a video of a guy who owns a motor home with a cat engine. 3116 or 3126. He had low oil pressure at 90k miles and put in a new oil pump and bearings. That fixed everything. My truck idles cold at 40 psi. Cruising cold at 60 psi. Warm idle at 17 psi. All within spec. My neighbor has a c7 in his lmtv and has 80 at cold idle and like 60 cruising warm and 40 at warm idle. In other words, more oil pressure than me. So I went to Empire Cat in Tucson to inquire about a new oil pump. She required my engine serial number which I had. If I recall correctly, the original oil pump part has been superseded like 4 times. The latest iteration is a Gerotor type. (is the original not a Gerotor?) She acted like they knew there was premature pump wear and changed the style of pump. I dont know this to be fact, but she was knowledgeable. There are two pumps for a 3116. A new and a reman. Both are like $1800 but the reman returns $1100 with your core making it $700 and change in the end. So, I would be curious to know how difficult changing the pump is and which pump you go with? I may be doing the same someday.... is this the pump you are getting? Thanks, and would love to see more pics!

20R-7247: PUMP GP-GRTR | Cat® Parts Store
 

GeneralDisorder

Well-known member
Steel Soldiers Supporter
2,000
5,127
113
Location
Portland, OR
WOOF! The oil pump drive gear teeth! That's not nice of it.

I would be tempted to just run it (the drive gear, not the shattered pump) but it would probably bother me forever and it could happen again and break another pump.

That looks like a sack of buttholes to replace too. :cautious:
 
Last edited:
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks