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Bought a 1983 Mack MH 613 and need a touch of help


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Hey all, 

I pulled this out of the some guys yard the other day and I am getting ready to start it but I have a question or two if someone could help. 

1. raising the cab, it says on the jack there is a manual release but I cna not find one anywhere, other trucks have them box on the passenger side. Either way this will not raise. The pump could be bad or there is a catch somewhere I am missing. I would appreciate any help. 

2. the brake pedal is stuck solid and the alluminum base is pretty corroded. Are these still vailable? 

Looking for some of the plastichrome parts, Are they available still 

Thanks in advance all. 

 

 

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That looks like it was driven to its resting spot a long time ago. What engine is in it? I'm not sure about your jack I'm sure they'll be a lock somewhere though. If you send a pic of the aluminum base for the brake pedal I'll see if it's same as a r model I probably have one. Your air valve that operates your brakes could possibly be what's seized as well. What's your plans for truck?

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The cab lift system contains a pump which is mounted on the RH muffler bracket. It's hydraulic. Operates like a common bottle jack. You use a rod to pump and turn a latch to release pressure when lowering the cab down. When you pump the latch must be in the close position (don't remember, probably clockwise). If no action could be shortage of oil (too probably after a long storage). The filler plug is already on the pump and you can use ATF and even used to get the system operational.

There's no catch. Cab locks are hydraulic and mounted below the cab airbags. When you start pumping the jack first makes the locks get loose and after that oil goes to the lift cylinders. Locks could be stuck (in theory) but you will see that if the cab tries to go up and locked near airbags. There's a security support plank on the right frame rail at the front below the cab, use it when the cab is raised.

The brake pedal gets seized in the aluminium base. There's a steel piston inside a cylinder bored in the pedal base which pushes the threaddle valve when you push the pedal. You need to remove the base from the threaddle valve and get the piston (actually a tappet) free. Hitting, heating, WD40 penetration are the ways to go. After it's loose sand off all oxidation from it and the cylinder surface and apply grease. The base and the tappet are NOT interchangable with R-model (RW, RD, DM etc) but unique to MH. And too probably not easy to find. The threadle valve is a standart brake valve, same as in R. The big pedal base with MACK script has tendency to corrode due to moisture in the floor mat. A difficult to find part either.

Also a weak point of MH is the gear shifter assembly. Could be found broken down or worn out. Front air tanks could be found rotten through where the aluminium steps are attached to them. Windshields and front grill are difficult to find parts.

Good luck on bringing her back to life.

Vlad

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Никогда не бывает слишком много грузовиков! leversole 11.2012

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1 hour ago, Ditchdiggerjcf said:

I hate for finding that truck before me.

Brake pedal sticks on mine if I let them sit very long. They are kind of a bitch to break loose again without tearing up the base, but it can be done.

Easy deal if you take the assembly apart, clean, put grease in it and put a good solid rubber boot onto the top of the plunger. The boot is the same as for an R-model, Watts have them in stock.

Никогда не бывает слишком много грузовиков! leversole 11.2012

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8 hours ago, david wild said:

Ever want to get rid of wife I'll trade plus $$ any woman that will power wash a truck is for me, she have a sister ?? 

That impressed me as much as the truck as well

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Welcome aboard :WELCOME:

Looks like you have a nice project to work on. I liked the video. 

Just my 2 cents....... Before you put batteries in it and start cranking. Change oil and filters and change fuel filters. 

Take out air cleaner and check animals haven't made a home in there somewhere. If the project is for entertainment value, I guess it doesn't matter much. It looks like a nice truck though, that deserves a fighting chance. 

I'm assuming you checked engine ,and its not stuck. 

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Keith 

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I have not rolled the engine over yet, but I did check the injection pump. I want to fire it once before I do filters so I can get the oil moving around in it. The plan is to roll it over a few times with the fuel shutoff in the off position so I can test to see if the rack in the injection pump stays free. 

Thanks to everyone here and some vigourus nonrecreational pumping I managed to get the cab up and over. I realized that it slowly leaks down fast so you need to outpump it. Fitbit says the heart rate got up to 135 LOL I think I am going to move it up to a heavier weight oil so it is a little less leaky or find a new pump. 

I am going to pull the aircleaner off and make sure it has not become an apartment. 

While this is a fun project, I really want to clean it up and for it to live again as a great looking working rig. I have a preference for older things and new lives plus the lack of electronics and relative simplicity is a benefit for us on the farm. I am debating putting a series 60 in it and a 13 speed someday but not sure. 

Thanks for following along! With the shutdown its cool to have some company with this, if only virtually :)

 

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Well, that pedal plate is killing me, and the electrical is also giving me some problems today. There is a solenoid, pictured that I think might power the cab, no ideal but it looks it has 12.8v to one side and 0 to the other with 9.2v to the small post. I might put a wrench across it and see what happens but I have a feeling something got hot at one time so I wanna take it slow with that one. 

I can get it to start to roll over with ether but not prime iteself so I filled the filters with fresh diesel and waiting for the batteries to charge now. 

Other than that I have been trying to get the pin out of the darn foot pedal to get to the plunger and that has been a challenge. I did put the tage for the motor, not sure what it means I will start looking it up tomorrow. 

As far as the wife, she knows she is apreciated, I am lucky but I feel this truck might cost me at the negotiating table for future disussions. Just Sayin  I think she gets what she wants now.....

 

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Thanks for the updates. 

The pic of the number off the motor , I believe that is just the oil cooler part number . The "   10   88  "   in the middle line is a casting date. Which could mean your truck is newer than you though . Or, it was replaced at some point. I have the same numbers on my oil cooler. Its an E6 350 4 valve. 

If you take a pic of the motor , I'm sure we can help. 

 

 

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Keith 

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7 hours ago, Countrylife said:

Well, that pedal plate is killing me, and the electrical is also giving me some problems today. There is a solenoid, pictured that I think might power the cab, no ideal but it looks it has 12.8v to one side and 0 to the other with 9.2v to the small post. I might put a wrench across it and see what happens but I have a feeling something got hot at one time so I wanna take it slow with that one. 

I can get it to start to roll over with ether but not prime iteself so I filled the filters with fresh diesel and waiting for the batteries to charge now. 

Other than that I have been trying to get the pin out of the darn foot pedal to get to the plunger and that has been a challenge. I did put the tage for the motor, not sure what it means I will start looking it up tomorrow. 

As far as the wife, she knows she is apreciated, I am lucky but I feel this truck might cost me at the negotiating table for future disussions. Just Sayin  I think she gets what she wants now.....

 

20200509_203122.jpg

20200513_100222.jpg

20200513_100044.jpg

Do NOT just wail on the end of that pin with a hammer. You will either break the mount or mushroom the head and it will never come out. Put some heat on it and some vise grips on the big and and try to spin it to break it loose.

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Here are some photos of the motor and of that pedal, the base is pretty corroded so I want to source a replacement somehow. I will try to put some heat to it today. 

I was a little scared as it is corroded alumimum. She did fire off this morning and it is dumping air out of the bottom of the high low shifter. I am not sure if that is a little ball valve that lost the ball or is just stuck in the unload position but I need the figure that out as well. 

 

Thanks for everyones help, here is yesterdays updates for fun 

 

 

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