Leak at the track tensioner. 306E2

[subdural]

2018. SN CAT0306EEE2W03692. image 1 is before - i tension the tracks and both the fitting and the bolt behind it snugged tight. if i run it for a bit, then come back. the tracks are slacky and there is this greese piled up.

where is a good place to start tearing something apart - or am i missing a seal on that bolt or something? it happens on both sides.

 

[Vetech63]

You can remove what you are calling the bolt and check the seat on the bolt and the valve. Make sure they both are clean and damage free. It needs to be tight, but don't overtighten it.

 

[BC Placer gold]

I had a similar situation on our Hitachi ZX120 several years ago. The grease fitting-“bolt” assembly itself was damaged (on the base where it seats). It was a quick and easy fix. Hopefully this is your issue.

 

[Nige]

The small hole where the grease is exiting is the "drain" hole for relieving grease pressure in the track tensioner when the tracks need to be de-tensioned. The fact grease is coming out of that port is an indication something is wrong with the valve, or bolt as you call it. Carefully remove the valve (it may be under some pressure) and inspect the tapered end of it. Also inspect the conical seat in the barrel of the tensioner where the valve bottoms out. There is no seal on the valve, it is a metal to metal joint at the bottom. If you need a replacement valve the P/N is 154-2237.

 

[subdural]

as always this forum is the best! id be rippn apart stuff i had no idea what to do, now i can make a great repair! TY ALL

 

[subdural]

The new one from cat seems to also have the nipple attached, i think the one in the above photos was an aftermarket.

 

[Nige]

The genuine OEM part is one piece, always has been. The nipple/zerk is not separate. Generally a leak from the nipple when attempting to tension the tracks is the most frequent cause of that valve requiring replacement. Do NOT assume that replacing the valve is going to fix your problem though. Carefully inspect the conical face at the bottom of the hole for damage as well.

 

[subdural]

so the Left track with the replacement part is working great. on the R track, i put in greese and it does tension, but soon as i run it a few hundred yards its slack again. i can hit it with the greese again and it goes to good tension, then i let it sit overnight once and it was slack. anyone know what i should pull off first? i do not see any evidence of the greese from what i can see.

 

[Nige]

So you replaced the track adjuster valve on both sides.?

If you did and the RH track is still de-tensioning then most likely the grease seal in the tension cylinder has failed. The track adjuster will have to come out and be re-sealed. See the attachment.

 

[subdural]

ill start to make that repair. thank you for the PDF!

 

[subdural]

this unit has metal tracks - do i start as i have seen with taking out the 'main bolt' on the tracks to remove them, then this tension cylinder will slide out? or is it a different way to get at these failed parts. thank you.

 

[Nige]

Find the master link of the track (#2) which is held in place with a cotter pin (#7). Position the tracks so that the master pin is over the front idle. Remove the cotter pin then beat the master link pin out of the track to split the track.

 

[subdural]

does the pin fall out to the inside of the tracks? so i can strike it from the outside - or do i have to hit it from the inside of the tracks to make it pop outside the tracks? and thank you!

 

[Nige]

Knock the master pin out from the side with the cotter pin towards the other side. Usually the cotter pin is on the outside.