B7100 Radiator drain plug question

[ant126]

Hello, I recently purchased an 81 Kubota B7100 HST and I am in the process of changing the fluids and filters. I have downloaded the WSM for the tractor and it came with the illustrated parts list so that is great too. They are really helpful. The only thing I am not very clear on is getting this drain plug on the bottom of the radiator to open. The lower radiator hose looks good and I can see it will probably be a mess if I take that off, so I would rather just drain the radiator with this plug if I can, but I don't know how to open it. If anyone has drained the radiator through this plug any insight on this would be great.

Thanks for your time!

 

[85Hokie]

Hello, I recently purchased an 81 Kubota B7100 HST and I am in the process of changing the fluids and filters. I have downloaded the WSM for the tractor and it came with the illustrated parts list so that is great too. They are really helpful. The only thing I am not very clear on is getting this drain plug on the bottom of the radiator to open. The lower radiator hose looks good and I can see it will probably be a mess if I take that off, so I would rather just drain the radiator with this plug if I can, but I don't know how to open it. If anyone has drained the radiator through this plug any insight on this would be great.

Thanks for your time!

The drain plug is not really a plug - rather a petcock or drain cock. Most are a T-handle, a little spin and the fluid will come out WITHOUT having to remove anything!

I feel your pain - I had one that had not been opened in a long time, it was solid brass - as soon as I applied a little pressure, yup - you guessed it!!! Broke right off!!!

Get cha a pair of needle nose and see if you can get it to "loosen up" - if you break it off - you will be removing the radiator - which is not a huge deal!

 

[spd164]

The drain plug is not really a plug - rather a petcock or drain cock. Most are a T-handle, a little spin and the fluid will come out WITHOUT having to remove anything!

I feel your pain - I had one that had not been opened in a long time, it was solid brass - as soon as I applied a little pressure, yup - you guessed it!!! Broke right off!!!

Get cha a pair of needle nose and see if you can get it to "loosen up" - if you break it off - you will be removing the radiator - which is not a huge deal!

Yep. When I replaced my rad and hoses I sprayed the petcock with wd-40 and uses channel locks to very gently wiggle it back and forth until it broke loose and turned freely to open. Oh, and I was worried because it didn't look like the stream of coolant exiting the rad would clear the front suspension and would splash all over making a mess of the shop. Don't be. It clears just fine. Good luck. I love my 30 year old B7100. Tough little workhorse for sure.

 

[ant126]

Sorry I didn't thank you all sooner for the tips. I ended up changing everything but my coolant when I changed the fluids because the coolant actually looked really good. It turns out though that I am doing a little radiator work right now and I went to drain the coolant using the petcock and I turned it and it will only move 1/2 a turn or so before it stops bumps against the bottom of the radiator and cant be turned anymore, but nothing happens when I turn it. No coolant comes out. I guess I will leave the draincock alone and just disconnect the lower radiator hose to drain the radiator.

 

[Dave_eng]

Sorry I didn't thank you all sooner for the tips. I ended up changing everything but my coolant when I changed the fluids because the coolant actually looked really good. It turns out though that I am doing a little radiator work right now and I went to drain the coolant using the petcock and I turned it and it will only move 1/2 a turn or so before it stops bumps against the bottom of the radiator and cant be turned anymore, but nothing happens when I turn it. No coolant comes out. I guess I will leave the draincock alone and just disconnect the lower radiator hose to drain the radiator.

In some areas of the world, insects make their nest using mud. In my area of Canada, any small hole, like a drain cock, is soon plugged with dried mud. Get a bright light and look for the opening in the drain cock. Use a small drill bit turned by hand to loosen any material that is stopping the coolant from draining.

Dave

 

[ant126]

Dave;

It was extremely dry and hardened mud in the petcock. Possibly mud daubers (they are very common where I am). You couldn't even tell there was a hole on the bottom of the petcock the mud was flush with the bottom of it. I used a small cotter pin and it cleaned out easily.