Leaking top waterpump housing bolt. Silicone? Ian?

[Willtill]

Ian (or whomever may know),

Think you had that weeping topmost water pump housing bolt; and you fixed it with silicone? I've torqued it to spec, but she still weeps a little. How exactly did you apply the silicone? Back the bolt all of the way out and coat it? Or did you back it out just a little bit and then do it?

Am I going to get a lot of drainage when I do this?

 

[Gothlander]

There should be a copper washer on that bolt, just coat the the washer on both sides. You can quickly remove the bolt and place your finger over the hole to stop leakage but with the radiator cap left on there should be minimal loss. Just don't do it with the engine hot or it will be under pressure and spray out.

 

[Willtill]

10-4, thanks Goth

 

[Mark Dunn]

Hi willtill,

I had the same issue and used a black, high temperature Permatex sealant to fix it. When you take the bolt out, check the underside of the bolt head (the sided facing the copper washer) for burrs. My bolt had a couple of burrs that had gouged deep grooves around the circumference of the copper washer, - easily enough for a small amount of coolant to pass. I filed the burrs off before refitting.

Regards,
Mark Dunn

 

[Willtill]

Hi willtill,

I had the same issue and used a black, high temperature Permatex sealant to fix it. When you take the bolt out, check the underside of the bolt head (the sided facing the copper washer) for burrs. My bolt had a couple of burrs that had gouged deep grooves around the circumference of the copper washer, - easily enough for a small amount of coolant to pass. I filed the burrs off before refitting.

Regards,
Mark Dunn

Interesting. Thanks.