update ...i just reassembled the valve today. two guys in the local bobcat parts dept. said there should be two of the black quad seals under the bushing washer. i put them in and the bushing washer stood out about a 32nd of an inch from it's seat, i assume that when the cap is tightened that gives the seals a little "crush".. so seals bushings ,spring washer, spring ,cup and bolt,cap and two allen bolts done . after doing this job with the engine pulled i can see that with some effort it could be done with the engine in place. i was working on the tilt section so no detent balls to deal with , both of my detents work fine and as this is to be my spare machine i don't expect the detents to get much of a workout in the future. i'm glad i pulled the engine, with the look around i saw the radiators were caked solid with oily dirt,so they went down to the shop..more $$. the throttle plate and lever on the engine needed to be replaced also . so with the valve parts ,engine parts ,new belts and hoses and the radiator work i'll have a nice little 743 ready to work for about 500$. jim
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I,m not sure why they would say to use 2 per end as you only use 2 per spool . A quad ring is not designed to operate with any crush.
So you are saying that you put two of the old style black square edged seals on each end of the spool as per instructions of your dealer and you were able to get it all together and it didn't leak , do you find that the spool isn't as smooth as it use to be , as it would seem like it would cause a bind , don't want to sound pestimistic but you maybe doing that job again soon ---- you say you can see how it can be done without removing the engine , it is hard but saves so much work
i only did the rear end of the spool. when i called parts, the guy said there were two seals under the bushing ,when i went to pick up the parts another guy filled the order and i asked him speciffiicly for the bushing and any and all seals under it ,he said there were two of the same seals under the bushing. when you put only one seal under the bushing and slide the bushing in place there will be room left for the seal to slide back and forth when the valve is worked this didn't seem right as it would lead to the seal moving around and getting torn ,so i went with the two square cut orings that he gave me. the valve still slides freely and i haven't put the engine back in yet so i don't know about wether or not it will leak. considering that this valve has given bobcat problems in the past with the cap breaking and leaking maybe this two seal deal is part of an upgrade ,i have never seen the old seals so i can't compare these new ones with the old ones, well the engine is not going in until monday so i guess ill call the dealer again . i don't have the book for this machine and i wouldn't be the first time i got bad info from parts... jim
Usually the steel washer /bushing has a lip that pushes against the seal and holds it in , I am a little surprized that they gave you the black ones I thought they were replaced with the green ones , but do think on some older machines you do still need the black ones ----did you notice the ears of the cap being thicker and the bolts longer ------also if I were doing it I would change every seal on all the spools of all the controll while I was right there as one of the other seals will probally be right behind in leaking
the washer/bushing has a lip on it but with just one seal in place it didn't seem like it would hold the seal in place as the seal was not thick enough ,it seemed like it would let the seal move back and forth a little . as for the black seals, i gave him the ss# and parts told me these were the ones i needed.i did get the upgraded cap and the parts guy seemed familiar with this whole upgrade thing ,like he's seen it many times before .also he had all of the parts in stock which for a machine this old is rare for my dealer. at any rate in a couple of hours a call to the dealer hopefully will clear this up. thanks jim
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Its your loader, but I too would encourage you to change all the spool seal and the detent balls after you have gone through the trouble to remove the valve.
Also if the detent quits working on your aux hyd and you want to run an attachment that requires continuos flow like a mower or backhoe, you will kick you butt.
The one on my 553 worked perfect for the first week or 2 after I rebuilt it the machine, then it quit.
I never pulled the motor or the valve during the rebuild but I may have to to fix the detent for running my tiller. The float one is nt such a big deal, I never use it, but the aux hyd is imo.
Ken
Yesterday I changed a few hoses on a 743 , this machine is in classic condition , the guy had it repainted , rebuilt motor + sunstrand pump and aot of other work done by the dealer , if you still have the motor out of your machine I would take a close look at and change if needed the outlet hose on the bottom of the valve as it is pretty hard to do in the machine , had to remove the bottom fitting and tube from the valve using crowfeet and about 5 different wrenches , I wish it were the seals as it would have been easier , this hose connects to a 90 degree fitting in between the aux hyd fittings and tubes on controll valve --------- I had the chance to look at the controll valve and this unit would have been fairly easy to change seals with the valve in place , but as I said before there are at least 3 different configuations of the controll valve and plumbing in the 743 and I remember one is hard to do in the machine ---------I have a set of the pliers from Bobcat to install the balls in detent and it works ok , but I seldom use it , I put the spool in a vise and clamp it where the clevis goes thru the hole as to not scare the spoll , the spool centering spring facing straight up put one ball and srping in place and cock the cover to hold it in , take a screwdriver and push the other ball in while hold pressure down on the cap , it's not hard , but get extra balls when doing this jos as it is easy to lose them -----------what did you do about the two seals in one bore ?
placed the call monday ,they sent my a copy of the tech service bulletin. my valve uses the black "quad ring" seals . 1 per ... i got my radiators back monday and now i've got work to do with my other machine so it looks like next week before everything goes back togeather. thanks jim...
