If you are planning on replacing your waterpump in the near future, plan ahead and order new bolts and studs before you do so. All of the bolts on my 49k mile XJS had significant rust and putting. I’m lucky they didn’t break off when I was removing them. The two studs at the bottom of the picture that hold part of the engine fan assembly were nearly stripped on the fan end. I was fortunate they also can out easily with a stud removal tool. Not shown is the countersunk screw, but it removed ok with a #4 pozi bit and an impact driver. The new pump uses a standard bolt instead.
You could probably replace most of the bolts with stainless, even though they aren’t quite as strong. I’m not using stainless, but I will use antiseize on the fasteners and studs.
The pump had been changed before, so this may not be typical. But corrosion such as this is typical in my experience where steel bolts go into aluminum blocks around water pumps on other cars.
I use GENEROUS amounts of Anti-Seize compound for installation.
The next guy thanks me!!
Actually, most of that looks like surface rust to me. There is one that looks bad, if I’m seeing it right in the photo.
When I see deposits like that I clean up the bolts on my electric wire wheel brush for a closer look. To tell you the truth I would probably end up reusing most of them and apply anti-seize before installation.
Paul
It’s WAY more than surface rust. Portions of the threads are eaten away on some of the bolts, with necking down where the shank meets the start of the threads. There’s also deep pitting in the shanks of some of them. If it was surface rust, I would have cleaned them up and reused them.
Bolts are cheap: good call.
The bolts were cheap, as was the stud with the hex on it. The plain long studs are $10 apiece. I tried to find generic studs that long, but had no luck. If someone hadn’t stripped the threads on them, they were in otherwise good shape.