While changing my timing belt I noticed in the bottom corner of radiator a leak. I've heard about the plastic end caps and I'm not sure if this is where the leak is. I had a Taurus and had a similar leak, they were able to do a one time only repair on the end cap. Is the Volvo similar?

It cracks because the plastic embrittles due to prolonged heat and thermal cycling. Repairing the crack does not fix the underlying problem, only masks it, and you are risking your engine to try this for more than a short period. Buy a new radiator. While there are some repair kits made for American cars, they won't fix this problem and you cannot buy a replacement side tank, so go for the new radiator.

I've never had to do a repair on a plastic radiator so I can't speak from experience. The motorcycle world seems to swear by that JB Weld stuff for fairings and other plastic parts so it sounds like a good option.
Ebay usually has new aftermarket Volvo radiators for sale.

So, after posting this message I go out and look at the car and hear an incredibly loud vaccum leak. Just behind the thermostat on the number one cylinder the intake manifold has lost part of it's gasket. Funny thing though, I plug the leak with my finger and there is no difference in the idle. It looks like I will be trying JB weld for the time being to cut down on costs and waiting for the weather to warm up, as if there isn't enough to do. Thanks for all the help.

I must tell you who ever said '1 time only' was BS-ing you. Any way... i just repaired my raidator (it's still drying) so i know the best steps to take AS LONG AS IT'S ON THE TANK metal or plastic. If the leak is in a hard to reach place then take out the raidator. Note the place it's leaking from. Throughly clean it using a solvent or alchol. Use a large grain sand paper to ruff up all surfaces before using it ensure a more than suitable hold. Then Use a good coat of JB WELD. I prefer the 18 hour set time stuff to the 4 hour, because i believe it is stronger. It will bond plastic or metal, or each to the other. It is very strong! and will hold indefinatly, ALTHOUGH i would only use it untill i bought a metal raidator. Follow the directions to a tee and allow at least 24 hours for it to set to make it perminate.

The adhesive has a tensile strength of 1800PSI making it a structural adhesive. Anything over 1000PSI is considered structural. This enables the end user to make permanent repairs instead of using mechanical, soldering or welding methods.

Can be used as an adhesive, laminate, plug, filler,sealant & electrical insulator
Stays pliable about 30 minutes
Sets in 4 - 6 hours
Fully cures in 15 - 24 hours
Water-proof
Petroleum, chemical & acid resistant
Withstands temperatures up to 500° F
Bonds to virtually any combination of iron, steel, copper, aluminum,
brass, bronze, pewter, porcelain, ceramic, marble, glass, plastic,
concrete, fiberglass, wood, fabric, paper - just about any material

Sory about the plug, but this stuff has saved my life about 5 times over.

Thanks all, Justus
--
Proud owner of a '96 960 & '90 740 turbo

I recomend changing the rad.I work in a volvo repair shop and commonly see those plastic tank rads craking on the top hose mount.We sell good quality after market steel core rads with a screw in a/c temp sensor for $289.00 Canadian plus tax.Save yourself a headache and get rid of the plastic.
Butch

Often, radiators can be repaired. If you trust the shop and feel they have a good work ethic, you're probably safe. When making your decision, however, consider how the repair cost compares to a replacement, which may give more peace of mind. With some of the good web sites around, you may find that you can simply replace the rad with a new one for about the same money.

Check:

fcpgroton.com
alloemvolvoparts.com
newandusedvolvoparts.com

Best of luck!