Hello, I have a Case 550G that was recently buried in a sandy creek up to the floorboards. While stuck with engine running, the transmission lost all pressure. Drug it out and hauled it home. Drained trans fluid and it was filled with water and sand. Flushed it several times with new filters and new hyd fluid until it was clean. When cold, it will have very low pressure. Rev it full throttle and it comes back into the green. After about 30-60 seconds, it drops back into the red at full throttle. Not enough pressure to release the brakes once pressure starts to drop. I was able to get it to go 10 feet forward and 10 feet back. However, it won't do that anymore. I did drop the trans and put a new charge pump in it. I did not replace the torque converter. I had read on here that if the driveshaft spins, then torque converter is working. Plus, the machine did move 20 feet...once. I bought a set of gauges. If I recall, the torque converter needs to be 70-90 psi and the charge pump needs to be above 300 to release the brakes. My torque converter is 50 psi at full throttle. The charge pump can get to 350 psi at full throttle. Both drop pressure pretty quick. At an idle, both pressures are essentially zero. I think the torque converter and charge pump are good. I think there is a massive internal leak somewhere. I thought about taking the valve body off the top of the axle housing to see if an o-ring is broken or cut in a spool. I did remove both relief valves and clean them. I didn't see anything wrong with them. No matter if you back the screw out, or all the way in, it will not change the pressure. I am hoping it is not a leak in the clutch packs meaning the axle has to come out. Looking for opinions. Anything is appreciated.
I have had a couple 1450B Case and a much newer 850G and I have been around an 1150 a good bit. I actually built a 1450B transmission once. But im still no expert. The 1450B had to have up near 500 on the charge pump I do believe. It could be so many things. But if I had sand in my tranny I would not run it, I would pull it, nomatter how clean it seems. I have seen a Cat transmission with so much crud in it that the clutches and steels couldn't make contact. You could have ate up your quad rings on the ends of your clutch pack shafts. Could be so much. If I remember correctly there are passageways through the clutch pack shafts to charge the packs that can be clogged. Could have a piece of grit sticking a valve. Just my two cents. Been years since I was in that 1450B tranny, and there are people on here that know much more than me. Good luck! Case is good equipment (except for those first 1650 and 1850 dozers), but parts availability is terrible. Thats the main reason I went away from them.
I appreciate your input. I figured in the back of my mind that the trans would need to be pulled. I was just hoping there was something I was possibly missing before I go to all that work. I have an 1150B track loader also, and it has needed a trans rebuild for some time now. I guess I'll get to do two and once...
Im looking at a couple of 1450B dozers right now. One of them is one I already owned. It was a good dozer all except the undercarriage is shot. It has the power 8 way blade too. The guy that has it has used it very little since I had it. The second was a DOT dozer. Has a super tight manual angle blade and a nearly new undercarriage. But the tranny won't hardly pull it. I can buy both for 5 grand. They would probably scrap for more than that...lol. The issue is..... The one I had was the one I built the tranny in and it worked great. His original plan was to combine the two and make one great dozer. I advised him to pull the bottom from the DOT dozer and put it under the one I had. Well he no listen to me... He starts robbing parts out of my old dozers transmission and putting in the DOT dozer. Now he has them where neither will pull themselves. I feel sure the DOT dozer needed the works and it's untelling what he did to mine. I have parts manual on 1450B and I been looking around some for transmission parts and they seem to be nearly non existent, so I will probably leave them be. But if you know a good Case parts source I would be pleased to know. My nearest is Briggs in Greensboro, NC about 1.5 hours away and they aren't the most ambitious.
Best used parts place if found so far is Schaefer Enterprises. 4535 State Route 3 North | P.O. Box 136 Wolf Lake, IL 62998-0136 (800) 626-6046 – Toll free (618) 833-5498 [email protected] Usually not too bad on shipping. I wound up replacing the charge pump and torque converter so far. That got my pressure back to normal in neutral. Pressure checks confirm track high low is good for both tracks. My internal leak is the forward reverse clutch. I took the rear shaft cover off and found grooves in the cover. I found another cover to try but haven’t had time to put it on yet. I’m hoping it fixes my pressure issue. If not, then the clutch piston seal is probably bad. Manual says to remove trans. But I wonder if I could pull the main shaft while still in the dozer???
I have a parts book for 1450B but nothing on 550. If my memory serves me correctly there is a clutch pack mounted on that shaft in a 1450B. With those there is no way to pull it without taking tranny out. I have worked on Franklin Logging Skidder trannys a lot and they are very similar so its hard to remember which one has which tricks. But im thinking on the 1450B that you have to set the preload on those shaft bearings with shims under those end caps and a dial indicator which is hard to get right because at the factory they had a jig to run them enough to relax the bearings and that way once its under power nothing changes. The 550 could be an entire different animal though im not really sure. One more thing I thought of is I think there is a big snap ring type device that held the clutches and steel in the clutch pack, and if they break when the pressure tries to load the clutches the fluid just blows by. That would be a big coincidence if that happened but stranger things have happened. I will check out Schafer. I think the 550 was made several more years than the 1450B so parts for the 550 may not be as rare but I really don't know.