Question about disassembling the accumulator

[MikeOConnor]

Item #2 That unit is the accumulator all by itself. The rest of the stuff in the picture is the apparatus that utilizes the stored energy to activate a cylinder, a valve of some kind, or a control rod. You said somethng was leaking. A little or a lot?

I'd put it in the middle of that "a little" to "a lot" spectrum. Introducing a new term, I'd call it "mop-able". I isolated the leak to the charging pump, talked to Terry about it, further isolated it to the pump itself rather than the little nipple fitting, and he sent me a rebuild kit for the valve assembly. The conversation went like this;

Terry; "the oil appears on the nipple?"

Mikey; "nope, it's showing up on the spring on the valve."

Terry; "Ah, you've blown the seals in valve, I'll get a rebuild kit to you on UPS."

So I think this happens with some regularity.

I've put a picture of the kit on this post as an attachment -- the two biggest circles (black, and white) are O-rings, the next biggest is a seal, and the little ones are all O-rings.

Terry described what to do. He cautioned me to measure where the spring-retention nuts were BEFORE I took them off, so I could get them back in the right place -- they control the pressure. I imagine the "right" way to do this is put some kinda pressure meter on that nipple fitting, but he said "just put the nuts back where they were, you'll get within 100 pounds." <grin> A guy after my own heart.

 

[J_J]

Mike, There is a correct pressuue for the charge pump, and he should have told you, but yes the number of threads showing on the stud after you have tighten them is a good start. Your book should say or maybe not what the correct pressure is. I believe this unit is the unit that charges the variable speed transmission pump. I believe it is in the 200 to 300 psi range.

 

[Bob999]

I note you have an 1850. The 1850 (and the 1845) use an accumulator in the emergency brake system.

 

[Bob999]

Mike, There is a correct pressuue for the charge pump, and he should have told you, but yes the number of threads showing on the stud after you have tighten them is a good start. Your book should say or maybe not what the correct pressure is. I believe this unit is the unit that charges the variable speed transmission pump. I believe it is in the 200 to 300 psi range.

This link may give you information on the correct charge pressure.
http://www.braketender.com/accumulators.htm

 

[J_J]

Bob, You are right on. You are the only that have said this is the brake tender unit. Now, I see the purpose of the large spring. The charging pump I had mention in an earlier post has nothing to do with this circuit. I don't think the accumulator in this circuit is the problem either, but you should bleed off the pressure before working on the unit. The tender unit apparently is leaking. When and if you get it broken down, please post a picture of the tender unit

 

[MikeOConnor]

Yikes. 'Fella gets a project done, gets distracted with other stuff and never finishes off the thread. Sorry about that.

Here's how things wound up...

I talked to Terry on Monday -- "pulling harder" was indeed the answer. I wound up having to apply a fair amount of leverage, but evenutally it came out. The pictures of the valve and the piston show the two halves. I kinda reassembled the piston so's to get something (that big fitting on the right) to apply leverage to. See that white O-ring on the left side of the piston? That was a complete pain to replace -- getting the old one off wasn't bad, but putting the new one on was beyond me. I finally had to take the thing into Big Bruce the Mechanic at the implement store and have him pop it on with his Crusher Hands.

Third picture shows the seal that was probably the one that was actually leaking. Pretty amazing that it would fail, given that I've only got a couple hundred hours on the machine. But hey...

Put everything back together, fired it up, all good. Thanks for the suggestions gang -- sorry about the long delay in this followup post.

 

[J_J]

Mike , An old trick of mine is to put the o-ring in some warm hydraulic fluid for about 15 min, then you should be able to just roll the o-ring right on. A sandwich bag works good for this, as you don't get hydraulic fluid all over you hands.

 

[MikeOConnor]

I've never had trouble with an O-ring before -- but that white one isn't stretchy rubber, it's more like plastic. Very little "give" at all. Does the warm hydraulic fluid soften it up?