Yesterday I noticed that the brake on my 440B skidder (syncro range trans) seemed to be intermittently grabbing.
I noticed that a couple of times when I put in the clutch the skidder came to a stop even though I was on a hill and was not touching the brake. Other times it would roll normally. It was a cold day -5 and the trans oil was thick. It seemed to lose power when I was turning and that might be related to the brake grab or not. Has anyone else had this problem and our does anyone have any suggestions?
(https://forestryforum.com/gallery/albums/userpics/14177/Skidder%20001.jpg)
It sounds like you may have a combination of two problems, one in the transmission, and one with the brakes. First the transmission. You said it was -5 degrees. At that temperature the transmission oil gets real thick. I've seen hydraulics do some strange things at cold temperatures, things you wouldn't even expect. If the fluid isn't warmed up, maybe with some ice in it, and you put a load on the pump when turning it can bog down the engine. A dirty or plugged hydraulic filter can have the same effect. If you don't remember when you changed the hydraulic filter it's about due. It's cheap, easy, and might even help. Water in the fluid will make it turn milky white, even a small amount. That usually doesn't hurt anything, but if there is excessive water or debris in the fluid it may need changed too. Partially covering the grill in front of the hydraulic oil cooler might help keep the temperature up also.
As for your brakes, they could very well be partially engaged some of the time. If the machine stops just by pushing in the clutch check to see if the brake cover is warm. It's located on the rear of the transmission, in front of the battery box. If it is, you're dragging your brakes. The brakes are hydraulicly activated, so it may go back to your hydraulic system.
Lately it's been fairly cold here, temperatures in the teens at night and twenties by day. When I get to work in the morning I have been letting the skidder warm up for twenty minutes or so to try to avoid the problems you have been experiencing. So far it seems to be working.
Are we talking about the winching (mechanical or park type)brake or the service brakes?
Quotemay have a combination of two problems
At least :D
I should have mention that I had just drained the the trans hyd. oil and changed the filter the day before. The oil did have a lot of moisture.
I drove the machine again the day after I made the first post and when I noticed the (*Service*) brake sticking I tried pushing really hard on the brake pedal, it seemed to me that the problem might have been caused by a sticky check or bypass valve in the brake valve. It felt as if something unstuck and the pedal moved an inch more than it had before and the motor also picked up a few rpms. When I let off the brake pedal the brakes were not sticking any more.
QuoteWater in the fluid will
I think ice was the cause of the sticky valve so you were right.
While I was searching the archives for some info on 440 skidders I came across your posts about your fuel pump and your fuel tank. I think that this is the problem that I am having with my machine losing power. After I changed the fuel filters and cleaned the sediment bowl I noticed that I could see air bubbles now and then. Sometimes when I saw bubbles the motor would lose speed. I bled the system many times but the bubbles came back. I found some leaks on the pressure fuel lines coming out of the injection pump and tightening them cured that but I am still getting bubbles on the suction side. I saw that Frickman had changed the lift pump and finally changed the fuel tank. Today I am going to try running the machine off a jerry can and see if this cures the bubbles if not I will replace the lift pump.
And speaking of spending money The Tire Man is coming by this afternoon to replace one of the tubes on the front. I took a chloride bath the other day (see my post in the "ever think your having a bad day?" thread) when I checked the right front tire. I managed to get a new valve stem core in that tube unfortunately the left tube valve stem is to far gone.
Frickman do you run loaded tires?
BTW I raise grass fed beef up here in Vermont and we used to have a farm in Big Cove Tannery Pa (Fulton Co).
You can see some pictures of my Beeves and the farm on my unfinshed web page.
Kingdom Hill Farm (http://www.kingdomhillfarm.org)
I know all too well about having a chloride bath. Had two back tractor tires go on me during haying this last summer. Cost me around $175 /tire to have a patch and a boot put in. Not cheap but it got me going again.
When I ran a 440B a few winters ago we had similar problems with moisture in the system causing problems. We were 20 miles or so back into the bush so we ended up using the tiger torch to warm everything up before even turning the engine over. From there we usually let the machines run for 1/2 hour or so. I think I went through 5 or 6 hydraulic filters in one week. There was moisture getting by the hydraulic fill spout as the rubber seal fell off in the snow on one of the guys. He didn't think it mattered all that much and never said a word until after we had the problems solved. Needless to say we didn't have him working with us for too long afterwards.
Grassfed,
You must have read my posts about mounting the fuel tank on the roof. That was on my old 440. It worked well, you just had to stand on the winch to put fuel in. I don't have loaded tires on my current 440-B, and I don't miss them. I run 18 to 20 pounds pressure in them and they work well.
I looked at your web page, That is some pretty country where you live.
Grassfed
If you can mount a inline electric fuel pump as close to the fuel tank as possible this seems to help as it is much more efficient to push the fuel and try and pull it. This solved a similar problem I had on my versatile tractor. It actually was in a factory bulletin.
Stonebroke
A friend of the BILs has a 440A and had problems with loss of power and dieing once in a while. BIL worked on it and found the fuel line inside the tank had a pin hole in it causing it to suck air once the tank was down past 3/4 full. Its definitely is cold my detroit wants to skip at idle,takes 1/2 throttle to clean it out. I let it high idle for 10 mins then idle for 10 more before heading out.
Great tips thank you everyone.
I think that my bubble problem is pin holes in my tank pickup tube. I am going to try the electric pump back at the tank idea.
The tire guy came yesterday and we changed the tube with out too much trouble (other than$225). The tire guy said that he did not see many 440s with the tires loaded. I thought about asking him to pump out both tires but we figured that it was not worth the risk of screwing up the good tube and having to change both fronts and since I do not have front chains I will leave them filled for this season.
I should be able to finish it up tomorrow and be in the woods by Saturday. I added a picture to the first post so folks can see the skidder.
grassfed
The electric pump I put in is wired to the ignition switch. So you can turn it on for a few seconds to build pressure before you start to crank the motor. Seems to help espcially when you are bleeding air out.
Stonebroke