Strange CAT aftercooler bolts

[Njlarry]

Imagine my surprise after removing the cover plate all psyched to remove my 3126 aftercoolers to find these bolt heads. The CAT instructions clearely shows common hex headed bolts which these are not. They are marked on the heads 129 and F-C.
Any idea what socket fits?
Thanks for any guidance!

 

[Strecker25]

They’re just 12pt, my small socket kit had them so you should be able to find one at a local store pretty easily. mine were the same

by the way if you don’t have the spec I believe the torque on those is only 21ft-lb for when you go to reinstall. Be careful tightening them, that’s a thread you don’t want to strip

 

[Njlarry]

Thank you. I remembered about 20 ftlb but they look some kind of weird reverse torx head.

 

[Riptide III]

I also believe they are 12 point sockets.

 

[fwebster]

They are "E" Tox, (External Torx) sometimes called Reverse Torx. The design is intended to equally spread the torque around the entire circumference as you tighten or loosen the fastener. You see them a lot on heavy equipment.

 

[techmitch]

Imagine my surprise after removing the cover plate all psyched to remove my 3126 aftercoolers to find these bolt heads. The CAT instructions clearely shows common hex headed bolts which these are not. They are marked on the heads 129 and F-C.
Any idea what socket fits?
Thanks for any guidance!

They are "E" Tox, (External Torx) sometimes called Reverse Torx. The design is intended to equally spread the torque around the entire circumference as you tighten or loosen the fastener. You see them a lot on heavy equipment.

https://www.harborfreight.com/search?q=inverted torx sockets
https://shop.snapon.com/product/Low-Profile-TORX/7-pc-3-8"-Drive-TORX-Low-Profile-Socket-Set/207RFLE

 

[Njlarry]

Thank you. I never pass on an opportunity to make a stop ar harbor freight.

 

[mquiet]

We have those also on the 3196 to hold the cam shaft back from sliding forward.

 

[fwebster]

Thank you. I never pass on an opportunity to make a stop ar harbor freight.

Be careful with cheaper imported tools like sockets. If you don't get impact duty sockets it is pretty easy to roll the points off the regular sockets and damage the fasteners. Also, some Harbor Freight, Northern Tool and Amazon suppliers save money by leaving some sizes out of a set. I'm not usually a tool snob but I've been caught on both of the above problems so I stick with brand name US tools on things like sockets and Torx drivers.


Frank

 

[Njlarry]

Does anyone know the size? Harbor Freight seem to be the only place that sells by set and not individually. They should be only 20 ft lbs torque.

 

[Strecker25]

The size code is M8X1.3X70MM , does that align to anything they have?

 

[Njlarry]

They are 12 pt 8mm but also found that a 12 pt 5/16 socket works very well.

 

[Strecker25]

They are 12 pt 8mm but also found that a 12 pt 5/16 socket works very well.

Cool, did you get them off ok?

 

[Njlarry]

Got the port off no problem after about two hours but the starboard looks impossible. Re-thinking if I opened up a can of worms.