Trick to removing thermostat housing cap on Volvo Penta D4?

[tzaddi93]

I'm trying to change out my thermostat and can't seem to get the front cap off. Am I missing something beyond the two bolts?

 

[CaptT]

I haven't been in the housing in some time but I thought there was 4 bolts, two on top and two on the bottom, tucked away out of sight. . There were also three or four locator tabs I believe that makes it a bit more difficult to remove as it has to be pulled out in a straight line. . I know it was stuck, possibly the O ring or factory applied alignment adhesive.?? Sorry I can't be of more help as it's been a while and I'm not near my boat at the time but do look for the two other bolts.

Terry

 

[tzaddi93]

Thanks Terry, I'll look again but I only see 2 bolts diagnal to eachother. I removed the hose and valve assemble to make more room amd the cover would rotate about an inch, but didn't want to budge beyond that.

 

[CaptT]

Your right, after revisting this schematic I can remember the located tabs and I believe I used a brass hammer and a large pipe wrench to move it back and forth slowly until it finally departed the housing. I also used some WD40 to soak it to get it loose. This schematic may help.
https://www.marinepartsexpress.com/VP_S ... ousing.pdf

 

[tzaddi93]

Thanks Terry, that's about what I just did for the last hour. Good ol WD40 and elbow grease, worked it free. I'm always a bit too cautious.

 

[CaptT]

I'm glad you conquered it!! I'm like you, over cautious but always happy I didn't break something. My Dad taught me to use only a plastic or brass hammer on things that cost a lot to replace........sometimes the cost is in $$$$ but it could also be in something you can't replace...time.