Thermovalve A/B. Is it really needed?

[superdesi]

My thermowax valve (the one on the thermostat housing next to the coolant bleeding bolt with 2 vacuum hoses sticking out of it) had been broke for a while and today to get rid of the hissing sound I removed the 2 vacuum hoses attached to the valve and joined them together. Is that valve really needed or can I do without it?

[smufguy]

you should have posted this in Carb tech. I dont know if u badly need it, but aparently u were having vaccuum leaks. Grab one from the junkyard man. Its not that hard.

[A20A1]

You can do without it... just make sure you aren't bleeding vacuum from the secondary diaphrag. I believe that is what the thermowax walve was for. If it was for the Secondary then just grab the vacuum line from the carb and connect it straight to the secondary diaphragm bypassing the plastic "T" fitting.

[superdesi]

Thanks for the reply. I have fuel injection. The vacuum lines are #3 and #12 going to the valve. As per you photo, I think it applies to carb models.

[smufguy]

Thanks for the reply. I have fuel injection. The vacuum lines are #3 and #11 going to the valve. As per you photo, I think it applies to carb models.

you asked for the vacuum lines going to a thermovalve right on the Thermostat housing. On the efi, there is no vaccum sensors on the Thermostat housing. There is a coolant temp sensor, and a secondary fan switch and on a third one. There no vacuum ran sensors there. u sure u did not grab the wrong housing? take a pic of what ur talking about.

[superdesi]

you asked for the vacuum lines going to a thermovalve right on the Thermostat housing. On the efi, there is no vaccum sensors on the Thermostat housing. There is a coolant temp sensor, and a secondary fan switch and on a third one. There no vacuum ran sensors there. u sure u did not grab the wrong housing? take a pic of what ur talking about.

This is what I am talking about (the valve is located on the thermostat housing):


It has 2 vacuum hoses coming out of it (#12 and #3).


This is part of the valve that broke off. It has the letters A and B on it.



Does anyone have a honda part number for it? I tried explaining it to the parts manager at my local dealership and he started acting like I was crazy.

[nappyroots827]

well obviously it has a purpose if its there...im not actually positive of its purpose, i would assume once the coolant reaches a certain temp it allows the vacuum to continue through the valve or vice versa, id think of it as a circuit, once the coolant warms up it causes something in there to complete the vacuum circuit....as to what it actually connects to or is used for im not sure...but im sure its got a purpose, just get one from a junkyard for like 3 dollars, its not that difficult

[A20A1]

Yeah it either opens or closes a vacuum passage based on coolant temp.
Where do the vacuum lines go? It might be difficult to find new thermovalves... you can pull ones off old carb but they do crack easily... The small vaccum ports and the valve body itself.