URGENT NEED FOR 1445 CHARGING VALVE

[Raemelton]

Anyone:

We've blown the Charging Valve on our PT 1445. Tazwell is closed for the week...

is there an alternate source for this part? Anybody got a cross reference to another parts mfg?

-Steve

 

[MossRoad]

Welcome to TBN.
Hopefully someone can help you out.

 

[woodlandfarms]

I wonder if it can be temporarily Bypassed. Not ideal but......

Look in this group for a guy by the name of JJ. Send him a PM (he will probably respond shortly anyway). The guy is one of the hydraulic gods on TBN as well as a PT Owner.

 

[ponytug]

It looks like a PT specific part. There are several parts to it. Depending on what you have blown, it may be repairable locally.

Mine has twice worn out the seals on the pressure regulating valve (the big spring at the tail end). I have never disassembled one.

My understanding is that this part takes a hydraulic input, and then uses a pressure regulator to pull off a 600psi+ (my memory of what Terry said) stream to relieve the brakes, and pop a second valve for full diversion of the remaining flow. There must be some bleed/bypass to remove the pressure on the brakes, but I don't know how it is done. If you rebuild it, you could probably guess at the pressure from a CharLynn catalog, when you reset the regulator pressure.

All the best,

Peter

Anyone:

We've blown the Charging Valve on our PT 1445. Tazwell is closed for the week...

is there an alternate source for this part? Anybody got a cross reference to another parts mfg?

-Steve

 

[J_J]

I heard that.

My 1445 does not have a charging valve.

I do have a charge pump which keeps the VSP pump full of fluid.

I believe the the newer PT hyd systems have an accumulator which is used with the brake system, and probably has a charging valve to pressurize the accumulator to a static/working pressure..

Is the valve below similar to what you are talking about.

Excerpt:

DESCRIPTION
This integrated package features a MICO Accumulator
Charge Valve and a Haldex W900 Gear Pump to accomplish
the accumulator charge function. The function of a dual
accumulator charge valve is to control the pressure in redundant
accumulators used in two or more brake circuits. When
the pressure in either accumulator decays to the specified
low limit a charge cycle is initiated. The flow rate at which the
accumulators charge is constant throughout the charging
cycle . The charging cycle is complete when the pressure
in both accumulators reaches the specified high limit. The
brake circuits are protected from pressure spikes at startup
by an internal pressure relief valve. Excess flow from the
valve may be used for steering, cooling or implement
functions. A relief valve is required for these function

http://www.mico.com/sites/default/files/documents/images/84-463-001.jpg?1346850702

 

[ponytug]

Dear JJ,

That image looks like a great match. Well done!

Mine has a secondary, small, hydraulic accumulator attached. When I searched for it, the image above seems to be a Hydac design, and the manual is on this link. The Mico valves in the link in the previous post are a different physical design, but probably do the same thing. Parker also makes a version.

I don't know if the PT unit is a Hydac, but it looks close to me, and the ports have similar labels. BTW, I connected the vent port on mine back to the tank. I was tired of the oil blowing by the seal weeping out into the tub. PT makes a kit, which is a cut to length hose.

All the best,

Peter

 

[Raemelton]

SUCCESS!

Google "M930 Charging Valve"

Realize that it gets used in some coal mining equipment.

Skip over all the "BreakTender" entries (That is Power Trac too...and also closed all week)

Discover KET Inc. in Raven VA ... an awesome mining equipment repair and parts outfit.

Call. Buy. Overnight. Install.

WORKS!

-steve

Thanks to all for suggestions

 

[MossRoad]

Glad you got it going.
:thumbsup:

 

[ponytug]

Great to hear that you got it fixed!

I'm curious what the price was? (Not including the special 4hr rush freight. :laughing: )

All the best,

Peter

 

[cqaigy2]

Good deal, thanks for posting.

 

[MikeOConnor]

This seems to be the week for charging valves. I've got a new one for my 1850 that needs to be installed. Here's an installation trivia question -- does that rascal need to be bled after it's installed? I see a little tube-cap that looks a lot like the one that's used to bleed the hydraulic pump when changing the hydraulic filter on this thing. Just curious -- I'm waiting until Monday to call Terry and get the low-down.

 

[woodlandfarms]

I have changed mine twice and neither time was it required to be bled. not that this is right but Taswell never mentioned it. Do though installe the drain tube that they should be giving you.

 

[MikeOConnor]

Thanks! Good to know. Question about that drain tube. I just got the valve assembly (no drain tube) -- I guess I was assuming this was a "take all the stuff off the old gizmo and put it in the same places on the new gizmo" type project. Is the drain tube a "disposable" item that needs to be replaced each time?

 

[woodlandfarms]

On the charging valve, there was a nut that was "open" (had a hole in it) with a gold screen mesh in the head. PT made a change a few years ago and just routed that oil flow to a drain line elsewhere, instead of dripping into the tub. When I changed out my charging valve, Tazwell sent me an elbow and a hose, and I had to go get some other connectors as I chose to hook it to the drain out of the float mechanism.

This is a LOW priority mod. It may also have already been done.

Oh, and nice to see you again Mike. Its been a while.

 

[MikeOConnor]

Fascinating. How much oil dripped into the tub what that drain was open? I'm losing what I consider to be "a lot" (ie, a puddle on the garage floor every day), and "more than there used to be" (none). I assumed that it was seals (again). Last time, my local tractor-repair guys put new seals in (I'm not much with hydraulics) which is why this is my first time through. But maybe I'm fixing something that is actually normal behavior. I'll check with Terry tomorrow and see what the scoop is -- in the meantime, I'm off to do some mowing with a spare quart of 10w 40 in the backpack.

Ya -- the 1850 hasn't kicked up any puzzlers in a long time. Sorry to be gone so long. Thanks again.

 

[ponytug]

Dear Mike,

If you didn't drain the brake line of oil, it doesn't need to be bled. The oil flow through it flushes almost all the air to the tank on the first power up. A few brake cycles will flush any remaining air out of the brake line.

If you did drain the brake lines, it would probably be advisable just to speed things up.

The installation is pretty easy. I do ~90% before bolting the charging valve to the tub and doing the final tightening (and strain relief) after it is bolted into the tub.

All the best,

Peter

This seems to be the week for charging valves. I've got a new one for my 1850 that needs to be installed. Here's an installation trivia question -- does that rascal need to be bled after it's installed? I see a little tube-cap that looks a lot like the one that's used to bleed the hydraulic pump when changing the hydraulic filter on this thing. Just curious -- I'm waiting until Monday to call Terry and get the low-down.