Coolant is leaking out the back of the thermostat housing
Coolant is leaking out the back of the thermostat housing
i found where the civic was pissing coolant from, it's the back of the thermostat casing. It in between the housing and a metal pipe so I'm guessing it's just a bad O-ring? And what exactly is this metal pipe for? A connection pipe for the waterpump to thermostat? And do I need to take the thermostat housing to get to the O ring? Couldn't find any any info on this pipe and how to get to that O-ring so any info would be great. Thanks
If you think a good mechanic is expensive, try hiring a bad one
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Re: Coolant is leaking out the back of the thermostat housing

Looks like the upper pipe (11) can be unbolted (25) then you may get it pulled out far enough to slip a new O ring on..... or you may need to get it loose from the hose (10) to get enough room.. I don't know, it's not like that is something I replace every day.
Play it by ear, whatever it takes. The connection with the O ring will probably be pretty tight fit, may need a bit of prying to get them apart.
Last edited by ezone; Dec 21, 2016 at 12:17 AM.
Re: Coolant is leaking out the back of the thermostat housing

Looks like the upper pipe (11) can be unbolted (25) then you may get it pulled out far enough to slip a new O ring on..... or you may need to get it loose from the hose (10) to get enough room.. I don't know, it's not like that is something I replace every day.
Play it by ear, whatever it takes. The connection with the O ring will probably be pretty tight fit, may need a bit of prying to get them apart.
Re: Coolant is leaking out the back of the thermostat housing

Looks like the upper pipe (11) can be unbolted (25) then you may get it pulled out far enough to slip a new O ring on..... or you may need to get it loose from the hose (10) to get enough room.. I don't know, it's not like that is something I replace every day.
Play it by ear, whatever it takes. The connection with the O ring will probably be pretty tight fit, may need a bit of prying to get them apart.
If you think a good mechanic is expensive, try hiring a bad one
Joined: Dec 2011
Posts: 32,017
Likes: 256
From: Midwest. Aiming about mid-chest
Rep Power: 517 










Re: Coolant is leaking out the back of the thermostat housing
Pic came from estore.honda.com,
the bolt should just be a simple 6x1.0 thread, 10-15mm long should work, available just about anyplace that has metric hardware for sale....or a mechanics leftover nut and bolt stash.
Missing....so someone had it apart and forgot to install that bolt, and threw it in the leftover stash bucket, or thought it wasn't important, or..? Head gasket job was done and this is the result?
the bolt should just be a simple 6x1.0 thread, 10-15mm long should work, available just about anyplace that has metric hardware for sale....or a mechanics leftover nut and bolt stash.
Missing....so someone had it apart and forgot to install that bolt, and threw it in the leftover stash bucket, or thought it wasn't important, or..? Head gasket job was done and this is the result?
Re: Coolant is leaking out the back of the thermostat housing
Pic came from estore.honda.com,
the bolt should just be a simple 6x1.0 thread, 10-15mm long should work, available just about anyplace that has metric hardware for sale....or a mechanics leftover nut and bolt stash.
Missing....so someone had it apart and forgot to install that bolt, and threw it in the leftover stash bucket, or thought it wasn't important, or..? Head gasket job was done and this is the result?
the bolt should just be a simple 6x1.0 thread, 10-15mm long should work, available just about anyplace that has metric hardware for sale....or a mechanics leftover nut and bolt stash.
Missing....so someone had it apart and forgot to install that bolt, and threw it in the leftover stash bucket, or thought it wasn't important, or..? Head gasket job was done and this is the result?
If you think a good mechanic is expensive, try hiring a bad one
Joined: Dec 2011
Posts: 32,017
Likes: 256
From: Midwest. Aiming about mid-chest
Rep Power: 517 










Re: Coolant is leaking out the back of the thermostat housing
Yep hahah the head gasket was replaced.
The more I look the more bolts I find missing.
The more I look the more bolts I find missing.
sick of people half assing stuff.
Re: Coolant is leaking out the back of the thermostat housing
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Re: Coolant is leaking out the back of the thermostat housing
if you're talking about #21 on the diagram, it's part number 91314-634-000
https://www.hondaautomotiveparts.com...bC1sNC1nYXM%3D
If you're talking about #6 on the diagram, its 19305-PLC-A00
https://www.hondaautomotiveparts.com...w0LWdhcw%3D%3D
https://www.hondaautomotiveparts.com...bC1sNC1nYXM%3D
If you're talking about #6 on the diagram, its 19305-PLC-A00
https://www.hondaautomotiveparts.com...w0LWdhcw%3D%3D
Re: Coolant is leaking out the back of the thermostat housing
if you're talking about #21 on the diagram, it's part number 91314-634-000
https://www.hondaautomotiveparts.com...bC1sNC1nYXM%3D
If you're talking about #6 on the diagram, its 19305-PLC-A00
https://www.hondaautomotiveparts.com...w0LWdhcw%3D%3D
https://www.hondaautomotiveparts.com...bC1sNC1nYXM%3D
If you're talking about #6 on the diagram, its 19305-PLC-A00
https://www.hondaautomotiveparts.com...w0LWdhcw%3D%3D
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