M35A3 Overflow tank sight glass threads

[Mark3395]

I have a leaky sight glass on a 35A3 surge tank. I need to locate one but in the meantime want to just plug it but am having a hard time finding a plug with matching threads.

Does anybody know what threads go on that glass?

And BTW, who has new ones?

Thanks much.

 

[R Racing]

Are you talking about the hydraulic tank for the winch or the coolant tank ?

 

[sierra117]

If your are talking about the coolant tank I had the same problem I just bought a length of clear hose I believe it was 1 inch in diameter clamped it over the sight glass hole put a plug in the other end of the hose and it seems to be working fine and on the plus side because of the clear tubing I can easily check the coolant level.

 

[AceHigh]

Mark, I just went to Lowe's and got a brass plug (1/2" I think) and plugged it. I actually removed the tank and took it with me to assure a correct fit.

 

[glcaines]

Mine isn't leaking, but it seems to be worthless as you can't really see anything through the glass. Like AceHigh, I would simply plug it and forget it.

 

[Mark3395]

I got a small freeze plug for now. I like Sierra's idea of putting clear hose and a couple clamps to leave the coolant visible. for now though, it's the plug I seek. Will go to Lowe's and try to find the proper thread.

Thanks much.

Mark

 

[Mark3395]

I got a small freeze plug for now. I like Sierra's idea of putting clear hose and a couple clamps to leave the coolant visible. for now though, it's the plug I seek. Will go to Lowe's and try to find the proper thread.

Thanks much.

Mark

 

[garp]

it is a straight thread o-ring fitting. -8 if i remember right. NOT pipe thread.

 

[CatMan]

M35A3 Coolant Sight Glass

I would try checking in with the local Heavy Duty radiator repair shop. Those sight guages are used on lots of commercial equipment. If there is a replacement available, they probably have a source.

Cat Man

 

[CobraCDR]

Please be sure to follow up and let everyone know if you find a vendor for replacements.

 

[YOUNG GUN]

it is a straight thread o-ring fitting. -8 if i remember right. NOT pipe thread.

It's definetely NOT pipe thread, but also not sure what size it is.
Mine was leaking badly one day, and all I had were pipe plugs; I drilled it out, re-tapped it NPT, and plugged it.

 

[maccus]

My truck leaked also when I got it. All it needed was a new O ring so I was lucky. I noticed the plastic threads were flakey at best. So I need to find a replacement soon. I did see one very late model truck with a different sight glass in it. It was not the plastic one but was real glass set in a brass fitting. I have a couple of places to call and see if they have what we need. Most all the brass type I can find have a pipe thread on them. But I have one vendor that has what looks like a regular thread on theirs. I will call him tomorrow. Does anyone know the exact thread size etc. that is needed??

It would seem that this is a very common problem. So it behoves us to find a replacement soon I think.

 

[YOUNG GUN]

I don't know if mine was the original, but it was glass, and not just the bulb either, the whole thing.
I know this cause when I tried to remove it...snap crackle pop, broken off almost flush and cut my finger on it all at once! Quite a wonderful end to my day indeed. Then I got to break the rest of the glass out of the threaded portion. I will however replace it with a new NPT sight glass soon.

 

[maccus]

I did some calling around today on the sight glass availability. Non pipe threaded ones are about impossible to find. So here is plan B.

In some of the responses above someone mentioned that even at best the sight glass is hard to see. That is right I think. So I am now looking for a pipe threaded sight glass and will mount it in a 90 degree elbow so one can see it better by only having to open the side panel. I need a male to female 90 with regular threads on the male end and pipe on the female end. I think I have seen that configuration at my favorite fittings store. If I can find the right components no modification will have to be done to the tank itself. Won't be going up to Rapid City until next Monday so hang in there. Garp I bet Whisler Bearing has that elbow. The pipe fitting sight glass is available from McMaster-Carr for around $10.

 

[glcaines]

My truck leaked also when I got it. All it needed was a new O ring so I was lucky. I noticed the plastic threads were flakey at best. So I need to find a replacement soon. I did see one very late model truck with a different sight glass in it. It was not the plastic one but was real glass set in a brass fitting. I have a couple of places to call and see if they have what we need. Most all the brass type I can find have a pipe thread on them. But I have one vendor that has what looks like a regular thread on theirs. I will call him tomorrow. Does anyone know the exact thread size etc. that is needed??

It would seem that this is a very common problem. So it behoves us to find a replacement soon I think.

Mine is a real brass fitting also, with a glass insert. As I mentioned earlier, it is difficult to see through, however. Fortunately, mine is not leaking.

 

[maccus]

Are there any vendor markings on the sight glass Gary? A regular thread to regular thread 90 would be easier to find I think.

 

[maccus]

OK. Just ordered a few of part number 1079K11. Second group of sight glasses from the bottom of the page. Decided to go with that unit so I could get the temp range I wanted. Garp says he might be able to come up with a 90 degree elbow that would do the trick. So nothing to do now but wait until the sight glass gets here.

McMaster-Carr

 

[maccus]

The sight glasses are in and they look good. Also Garp has just gotten the 90 degree fitting which he says looks like what we need. I am going up to Rapid City on Tuesday and will pick up the fitting. So on Wednesday or so I should have pictures etc. of the install. I believe we have what we want. A modification that requires no modification to the tank and one that allows us to see the status of the antifreeze level by only having to lower the right side panel.

 

[maccus]

Put the sight glass modification on today. Easy to do. Looks like what I wanted to end up with. Easy to see with just the side panel down. Thanks to Garp for knowing just what elbow to use. These CAT guys that have been in that outfit for a long time sure know their stuff. If you argue with them about CAT stuff you are sure to loose.

1......syphon antifreeze out of tank
2......remove old sight glass
3......install sight glass in elbow using pipe sealer/Teflon type
4......put "O" ring on elbow and install elbow in tank (when I got the elbow from Garp he had already put the "O" ring on)
5......fill tank back up with antifreeze
6......go for a ride to check it out

Here are the 3 items needed to do the modification.



1...sight glass McMaster -Carr part # 1079K11
2...-8 "O" ring STOR boss to 3/8 inch pipe 90 degree elbow CAT part # 6I-6547
3...the "O" ring itself is CAT part # 3K-0360

 

[garp]

I love buying stuff out of the Hose and Fitting Book. All shiny and clean.