Thermostat housing heater control valve thread

PostPost by: englishmaninwales » Tue Dec 11, 2018 4:43 pm

I?ve managed to damage the tapered thread on the control valve. I?m not aware that I over-tightened or cross-threaded it.....I am ordering a new one, there also seems to be some damage on the inner most portion of thread in the thermostat housing. I?m unsure if this is new or old damage. The outer threads in the port seem ok.

What is the best way to deal with this? I?m worried the same will happen. I know that Lotus used British pipe threads sizes on the cylinder head, can this port be cleaned up with a tap (but it is tapered?)

Thanks for any advice.
Malcolm
1966 Elan S3 Coupe
1994 Caterham 7
englishmaninwales
Fourth Gear
Fourth Gear
 
Posts: 747
Joined: 26 Jul 2013

PostPost by: tvacc » Tue Dec 11, 2018 6:51 pm

This has happened to me. Depending on how damaged it is, and none of mine have been that bad, I have always just used lots of sealant tape on the threads or some RTV and it has sealed enough for the low pressure of the cooling system. I had to buy a longer thread adapter from RD Enterprises (over here in the states) to grab the threads farther in.

Don't know if that helps.
Tony Vaccaro
LOONY (Lotus Owners of New York)
http://www.lotusowners.com
Drive Fast Take Chances
ElanGTS, 93 Caterham, 05 Elise,
99 Elise190, 05 Elise, 2005 MiataSpeed Turbo
User avatar
tvacc
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1161
Joined: 24 Dec 2003

PostPost by: miked » Tue Dec 11, 2018 7:35 pm

Malcolm,

I have always cleaned both these threads out with taps. I have a parallel one for the sensor and a taper for the heater valve. These threads are usually full of crud.
Usually the threads clean and the taper one cuts in a bit more allowing a good grip.
PM if you want to use them, I am in Warrington area.
Cheers Mike
Mike

Elan S4 Zetec
Suzuki Hustler T250
Suzuki TC120R trailcat
Yamaha YR5
Suzuki Vstrom 650XT
Suzuki TS185K
User avatar
miked
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1232
Joined: 29 Sep 2003

PostPost by: gjz30075 » Wed Dec 12, 2018 12:54 am

As was suggested to me, use JB Weld all around the threads, thread the valve in and let it sit for a few
days. I did this to mine and it is certanly holding in water. I'm told it'll thread right out if need be. If it
doesn't, I'll deal with it at that time.
Greg Z
45/0243K Sprint
45/7286 S3 SE DHC
User avatar
gjz30075
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 3482
Joined: 12 Sep 2003

PostPost by: tvacc » Wed Dec 12, 2018 1:05 am

gjz30075 wrote:As was suggested to me, use JB Weld all around the threads, thread the valve in and let it sit for a few
days. I did this to mine and it is certanly holding in water. I'm told it'll thread right out if need be. If it
doesn't, I'll deal with it at that time.


I was going to suggest JB Weld, but that is a last ditch fix. Sort of a permanent fix if you know what I mean. I would try the RTV first.
Tony Vaccaro
LOONY (Lotus Owners of New York)
http://www.lotusowners.com
Drive Fast Take Chances
ElanGTS, 93 Caterham, 05 Elise,
99 Elise190, 05 Elise, 2005 MiataSpeed Turbo
User avatar
tvacc
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1161
Joined: 24 Dec 2003

PostPost by: Panda » Wed Dec 12, 2018 3:56 am

Hi Malcolm, The thread is 3/8" BSP which is of course a tapered thread. It would be worth getting a tap and retapping the thread a little deeper and as suggested, using teflon (plumbers) tape. It has worked for me.
Alan P.
Panda
Second Gear
Second Gear
 
Posts: 156
Joined: 05 Mar 2011

PostPost by: englishmaninwales » Wed Dec 12, 2018 10:20 am

Thank you all for the helpful advice.
Mike, you have a PM about your 3/8 BSP taper tap.
Malcolm
1966 Elan S3 Coupe
1994 Caterham 7
englishmaninwales
Fourth Gear
Fourth Gear
 
Posts: 747
Joined: 26 Jul 2013

PostPost by: Craven » Wed Dec 12, 2018 11:17 am

Added problem is the valve must face in the correct direction with a water tight joint, crazy bit of engineering in my view.
I feel the JB weld is a practical easy solution, and is in no way permanent.
p1030327.jpg and
Craven
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1623
Joined: 14 Sep 2013

PostPost by: rgh0 » Wed Dec 12, 2018 11:24 am

With worn threaded connections such as this i use "Gas Tape" which is a thicker and stronger Teflon tape used for Gas fittings that make a more secure seal. You should be able to find it a specialist plumbing suppliers.

cheers
Rohan

l
User avatar
rgh0
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 8814
Joined: 22 Sep 2003

PostPost by: Craven » Wed Dec 12, 2018 12:37 pm

I don?t think a mechanical joint that has to support a hose that is a connection between a moving engine and the fixed bulkhead relying on a piece of soft tape a good engineering approach.
Craven
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1623
Joined: 14 Sep 2013

PostPost by: baileyman » Wed Dec 12, 2018 3:43 pm

Isn't the thermo housing pretty much already an engineering disaster?
baileyman
Third Gear
Third Gear
 
Posts: 362
Joined: 17 Aug 2017

PostPost by: tvacc » Wed Dec 12, 2018 3:55 pm

Sorry if I thought that JB Weld would be something hard to remove. It always has been for me. Maybe if you heat it, it comes off easily? I guess I have never tried to remove once it is on something.

Apologize for misdirecting someone.

tony
Tony Vaccaro
LOONY (Lotus Owners of New York)
http://www.lotusowners.com
Drive Fast Take Chances
ElanGTS, 93 Caterham, 05 Elise,
99 Elise190, 05 Elise, 2005 MiataSpeed Turbo
User avatar
tvacc
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1161
Joined: 24 Dec 2003

PostPost by: awatkins » Thu Dec 13, 2018 4:55 am

Why is it that in this application a JB welded joint would be removable? For example, Is it dependent on the surfaces being dirty? All of my exoerience with JB Weld tells me that if you used it in a properly cleaned threaded joint you would either have to heat it enough to soften the adhesive, or else destroy the valve in order to remove it.

What am I missing?
awatkins
Second Gear
Second Gear
 
Posts: 91
Joined: 23 Sep 2015

PostPost by: rgh0 » Thu Dec 13, 2018 10:20 am

Craven wrote:I don?t think a mechanical joint that has to support a hose that is a connection between a moving engine and the fixed bulkhead relying on a piece of soft tape a good engineering approach.



The tape is around sealing the threads. Happy to debate the engineering principles of thread sealants
User avatar
rgh0
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 8814
Joined: 22 Sep 2003

PostPost by: gjz30075 » Thu Dec 13, 2018 10:47 am

awatkins wrote:Why is it that in this application a JB welded joint would be removable? For example, Is it dependent on the surfaces being dirty? All of my exoerience with JB Weld tells me that if you used it in a properly cleaned threaded joint you would either have to heat it enough to soften the adhesive, or else destroy the valve in order to remove it.

What am I missing?


I don't expect to remove the JB weld in mine. I expect the valve to unthread cleanly and thread in again. IF it
should break apart, I'll deal with it then.
Greg Z
45/0243K Sprint
45/7286 S3 SE DHC
User avatar
gjz30075
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 3482
Joined: 12 Sep 2003
Next

Total Online:

Users browsing this forum: mbell and 25 guests