We have a mid to late 90's 1845C. Brake pins have stopped engaging, but pins seem to be in good shape when removed, and all linkages/springs seem to be fine. The person who normally operates it says he thinks one side quit before the other side. Removal of the pins/springs etc. on both sides show pins both in good shape and some wear on one side of the sprocket holes, though it doesn't look too bad. The cables and linkages all seem to be in good condition and operating properly. There is some side to side play in the sprocket assemblies, about 1/4 inch. The pins just don't seem to be engaging into the holes when tension is removed from the cables. I'm suspecting one of either several things, but want to know what someone who knows these machines thinks. 1. The sprocket holes are worn just enough to prevent the latch pins from engaging into the holes. or 2. The sprocket bearings are wore enough that the sprocket has moved too far away from the latch pins to engage. 3. The spring within the pin housing is wore so that it will not fully push the pin into the sprocket holes. 4. Perhaps the cables are not moving enough to release all tension on the springs. I don't know what could cause that. Anyone have an idea what the most likely problem is?
So you already have disassembled the park lock far enough to see the operation of the pins and looked at their condition, that's good, were the pins badly rounded where they engage the sprocket? I have seen the park tubes ripped right loose from people jamming them with the park lock engaged or engaging it still moving but you would have seen misalignment of pin to sprocket upon inspection. I have seen those sprockets rounded out where the pins sit pretty good and still hold, but the play is an issue in a couple ways. First it means the park pin has to travel further to engage but more importantly it sets the axle bearing running clearance , or should I say preload, I would pull the cotters and pull the sprockets up to tight and preload will not be an issue at all as they are slow running shafts and heating is not an issue. Probably a good idea would be to remove the tires so end play in the axles can be observed to make sure it is eliminated if present. Once that is done I would reassemble the pins, springs etc and connect the cables, apply the park lock to see how much slack is in the cables when the pin is sitting up on the high part of the sprocket before it pops down in. If I were doing the job I would set the cable length till the pin just disengaged the sprocket when the park is released, the cable length is set by the clevises. Of course this all assumes that the lever travel is not hindered any way that would keep the springs tensioned that the clevises engage. Concerning the tension of the pin springs, it should take fairly hard effort to pull the pins by hand.
I am having trouble determining if the pins/tubes are lining up with the sprockets. The tubes are not set at a 90 degree angle from the sprocket, which is strange to me. Could the tubes be bent? The cables are also rubbing hard on the end of the tubes because the tubes are not pointing inline with the cable pull. The tubes are facing somewhat forward, not directly outward towards the sprocket. I can't find any pics that would indicate this is not the normal angle of the tubes. But it does seem to me like the tubes may be what are preventing the pin from fully engaging towards the sprocket. The pins are not badly rounded. There is only slight wear.
I mean "backward" not "forward". The tubes seem to be angled towards the rear, not the front.
If the face of the tube is not parallel with the sprocket you are most likely looking at the problem, If the tube is badly damaged there is a kit for repair consisting of a new tube and a brace I believe available but obviously the job takes some cutting and welding skills. Reread your post and adding info, the tubes are probably not bent or you could not have removed the pins through a bent hole, the machine frame is flexed at the weld enough to allow misalignment. Not saying you couldn't correct those tubes position but I think it wise to start with new stuff. The cables should come out of the tubes dead center, if they are rubbing the ends of the tube you have serious misalignment. You know of course that is simply caused by abuse, that is a pretty strong park assembly and as I stated in the previous post it probably had the pins thrown in while the machine was still moving, I doubt that they could be damaged by trying to drive with it engaged but totally wouldn't rule it out .
Ok, after looking at it again, I am confident this is the problem. The tube faces are clearly not parallel to the sprocket. I am amazed that they are still attached. Is it possible to heat the tube and then bend it back into alignment? I am suspicious that one of the welds may be compromised and allowing water in. Is there anything else I should check for damage given the likely scenario that someone has applied the brake while driving and bent the tubes in this way? Thank you for your help.
There is no other way but the evidence is all there, the system is stronger than failure by normal use. We sold hundreds and very few experience that failure. You may attempt a repair as you decide. I believe there could be an internal brace that must be bent also, I know later than the 1845c series had a internal brace but not for sure about that. I was going to copy the park lock parts page to this post but am not smart enough, computer skills came along much later in life! There is a kit listed , Item 47 is the tube but over in the numerical section it gives an H number kit. I don't know what it consists of, a dealer probably could. Go to casece parts page, 1845C model park brake you can see the whole mechanism.
I recently completed an O/H of a mid 90's 1840 which I believe uses same concept of brake pins. Had a similar problem on left side and found the internal bracket broken off and distorted. Had to remove tube and bracket, straightened things out same as other side and re-welded. see pics. Sprockets had rounded areas which I also re-welded.
Cajun1986, Looks good! We had to fix one a few years back we the bushings for the pins were broke right off. To line them back up we used a shaft long enough to go through both bushings, believe it was a one inch shaft. Then after welding them in to get the shaft out we cut it to allow one at a time to slide out. If I was doing more than the one I would make a jig to clamp two shorter shafts together that could be unbolted to allow them to come out and still be used on the next machine.