Ricky Beals

Yes sir I purchased it thinking I had to replace bushings. The black insulators look good but I can see where one of the T’s have rubbed the box. Going replace them also with ATRO poly

Mechohaulic it has grease zerks on outer top but the drivers has broken off so I’m betting it hasn’t seen grease in a long time You thinking taking off cap, nut with bolt, two washers and check for up and down movement

The wheels walk I have driven it backwards with the bed up. Have not made a sharp turn with the bed up. Tie rods bushings are coming out. I have two that are in line with drive shaft. I have to pull the big dump cylinder to have it repacked. I have a 32,000 lb excavator. I wondering if I shouldn’t take that dump bed off before I do all of this. After I release the big cylinder and hoses nothing holding it on but two pins at the rear. Take them out and lift that bed off. I can take a video of driving it backwards with turning tight radius and showing how much it walks out. It will be next week when I’m down there. macks so I understand your process place jack under say drivers trunion. Jack up till both sets of tires are off the ground? Then wedge big bar between springs and frame and check for movement.

Ok I understand it looks like I will know when it gets tore down. Looks like I’m going to need to inspect those bushings and hope like hell it’s all good. My older friend is a welder/fabricator. The area sees a lot of log trucks but for some reason not a lot of Mack’s in our area. Thanks for the input.

And yes Macks I did think that I could replace the bronze bushing with a polyurethane bushing. After talking with ATRO he explained to me that ATRO didn’t make a poly bushing to replace the bronze original. If I understand you correctly your saying there is no poly replacement and it has to be replaced with original bronze bushing.

I was going to assist a older gentleman that has done a few in the past. I like to at least have some knowledge of what’s going on. I didn’t see any cracks in bar where they enter the saddle on inside of truck. I’m really hoping those saddle’s and bar are not needing replaced. I’m hoping all that’s needed is to replace the bushings and pads. Truck has always been in Arkansas so rust shouldn’t be an issue. I may call axle surgeons of arkansas Monday and see if they know of a qualified spring shop that has done a lot of mack Trunnion. I think we can do the swap if it’s just a bushing exchange but probably going be out gunned if bar and saddle has to be replaced. Can you guys offer me any idea on how to check and see how bad Trunnion is. Or is this something that will not be known until everything is off and your looking at the bare bar.

When I purchased this rd I knew the Trunnion needed replaced. I read where a lot of people had replaced their Trunnion with polyurethane. I was able to reach out to ATRO to see what was available for my truck. Jay at ATRO said they didn’t have a replacement for the bronze bushings and as far as he knew I would need to go with them. Has anybody here changed out bronze to polyurethane and if so what company did you use. Rear suspension is 44,000

I try and support my local Mack dealer but man they are just to high on those parts. Window regulator is 120.00, RD air filter is 99.00. I look on line and see doorman has the regulator for 59.00 and of course a lot of different options on air filter but most are half price. Guess I’m just a little tight and wanting to vent.

Moparmike !! Check your pm. I sent you one about a question you asked in the past on your RD688

Thank you Onyx610. Your time is appreciated. Yours to JoJo.

When I try to add a photo I get the message my file is to large. The photo is taken with iPhone. I have uploaded photos before from phone without getting this error. Anybody have a clue what’s going on.

Did the Mack RD 686 come with the informer on the side of the air cleaner? I have one and don’t have a clue if it is even working or working correctly. After reading a little on it they advise to use a vacuum pump to check it. Any other way to check one? I can’t think of anything I would need a vacuum pump for. I’m going change the air filter because I don’t have a clue how old that one is. The informer is showing very little restriction but don’t know if it even is working.

Thanks guys a lot of good advice. I didn’t prefill the oil filters but will in the future. I will prefill the fuel filters, I have a transfer tank that has a filter that I can get diesel from and know it’s clean. Ok I’m guessing I can get a test kit and check my coolant. What do you want your ph at? Never really thought about coolant ph. I just check to see how cold it can go without freezing.

67RModel that’s sound advice. My RD686 does not have a coolant filter that I can find. Mackpro I ordered a belt wrench this morning that was used for those specs. one more question guys. I’m changing the fuel filters and was wondering if I need to fill them with something? Some say Lucas fuel injector cleaner, some say diesel and some say mystery oil. I have never changed a fuel filter on a truck. A little knowledge here would help. Like what do you guys add or not add. I’m trying to start out on the right foot and I’m a big believer in maintenance. Got her all greased up, oil changed and now going change fuel filters.

No I don’t have a operating manual and was just needing for future use. Thanks

Mechohaulic you stated proper filter wrench and I was wondering what you were referring to? Onyx610 what do you use to remove the metal canister?

Well today was the first time I have ever changed the oil on a big rig and what I thought would take an hour took all day. I didn’t have anything to take the centrifugal filter housing off with. Drove 45 minutes one way to get a strap wrench and it wasn’t big enough. Drove back and got what looks like a big set of pliers and they wouldn’t work. Waited on a friend to get off work and borrowed his 25 year old snap on strap wrench that would take 3/8 or 1/2 ratchet. Finally after some torque and 1/2 breaker bar got it off. I put it back on hand tight but those big pliers seemed they would crush or dent it? I’m thinking of trying to find a metal strap wrench that will fit filter and metal canister? what filter wrench do you guys use? What filters do you guys run? I bought mack since I was at dealership but don’t want to drive down just to get them. May look for Wix filters that replace them. also didn’t see a crush washer on drain plug. Nothing but a bolt. Should there have been one?

Onyx610 would you happen to have something that shows what those numbers are to. 1 through 29

Thanks Onyx610

Can someone post the schematic of a 2000 rd fuse panel. Thanks Ricky

I got a question about the dump bed part. I was told at dealership the main cylinder needed repacked. We are expecting a lot of rain so I raised the bed. The bed is still up and hadn’t leaked down at all which I felt like it would. Which brings me to another question on how does the bed raise and lower. I understand when I engage the pto it starts the pump which raises the bed thru hydraulic fluid. Does the pump also drain the fluid out of cylinder to lower it? I guess I don’t know what is keeping it up with truck shut off and if the cylinder needs repacked wouldn’t the bed leak down.

Ok when I turn the control to Ac Max,Norm,Vent,Heat I can hear air. If I turn it to Off or Deff I can’t hear air. So is there one of those items that ONYX610 posted or multiple? Thanks

Didn’t really understand your answer. The ac system is off, fan is off. When I kill the truck I can hear air in that area and hear it best from the bottom vents below the AC controls. I’m thinking it’s something behind that ac box but have no idea what it is. What solenoid are you thinking is malfunctioning?

When bringing the 2000 rd688 home yesterday I was watching the air gauge and the red and green would peg 120. The green would stay at 120 but the red would move down to 100 then bounce back to 120 just to start back down to 100. when shutting truck off I can hear a lot of air coming out of the ac vent in middle of truck. Any idea where this is coming from and how to access it? Thanks Ricky

Posted a new photo in the original post with new question. Trying to see if the single psi gauge came standard on this truck or if it was an add on. It hasn’t moved showing any air so not sure what it’s for. this may be a boost gauge. I read where it doesn’t show boost unless there is a load on truck so may be why I have seen it move.