I have a small leak, is there a product I can use to plug it? Where do I pour it in? The reservoir or the radiator cap. I can not see my radiator cap anywhere. Where is that while we are at it?

TKS

The black pepper MIGHT be the only thing you MIGHT want to try. Any of the aluminum powder based "stop leaks" will plug up your heater core.

Just replace the radiator. It takes all of 30 minutes! You will save yourself a world of pain later. Trust me. Been there done that.

You have no "radiator cap" its on the coolant tank, passenger side inner fender with the green or black plastic cap and white bottle.
If you have that aluminum radiator with plastic tanks you will have to replace the radiator as it has begun to rot out to the point of no return. If you have the copper radiator a shop can repair this quite easily.

If you need to buy a "little" time and I mean little you can use ordinary table pepper, ground not whole pellets. Go make yourself a burger and take the pepper shaker with you to the car this way your wife wont suspect much. Shake some on your burger and dump about 2 tablespoons worth into the coolant bottle and start the engine. Pepper will be circulated through the system and when it passes the leak it will try yo flow out with the coolant and get trapped in the small holes. Now after a while in the water it will expand slightly and plug the holes (we are talking pinholes folks) and being organic in nature wont affect the water pump seals or plug heater core.
Pepper specifically black pepper is rotten red pepper and when wetted will expand a great amount.

Just make sure the pepper makes it back to the kitchen, don't want to read about the fellow brickboarder who lost his head to the grindstone!

988

You're better off by far in replacing the radiator, ESPECIALLY if it has plastic tanks. Figure it as just another maintenance expense.

If the tanks are OK, you can do a temporary repair with a stop-leak additive. I prefer Barr's Leak, since it is somewhat easier on the water pump seals than Alumaseal.

If the leak is in the metal heat transfer matrix, you can fairly easily repair that yourself, or have it done at little expense.

There are several methods to 'repair' the little tubes; the first is to use a tiny pair of needle nose pliers and crimp the damaged tube just above and below the leak. Then, put some Barr's Leak into the system for a couple of days, then drain the coolant and replace it.

For an old-time quickie repair, you can use the white of an uncooked egg to stop leaks. This sounds silly, but we actually take a few eggs to the racetrack with us for instant repairs of small water leaks. The egg white cooks quickly in the hot coolant, gets chopped up in the water pump, and then gets pushed into any leaks. We have run race engines for many, many laps using this repair. I suspect it will solidify into a permanent repair if you leave it in there!

If this were my car and I intended to keep it for a while, I'd consider having a custom raditor made up. You can then have good aluminum end tank, extra rows of cooling tubes, and they can even add a fill hole on the top. Considering the system Volvo used on your model, I'd have a fill hole that accepts a large flanged pipe plug, not a radiator cap. This would also simplify the problem of getting any trapped air out of the system.

Good luck! Steve

I agree 100% with the posts below. If you are just buying time and it's a small leak then the BARR's Stop leak works well. I would drain a little anti freeze out of the Block so you know the fluid level is below the hose on the Overflow tank. Because of the way Volvo has their Overflow tank as the Radiator access I would mix the BARRs with some antifreeze. Start engine and let idle as you slowly pour this BARR's into the Overflow. After it's all in continue to fill the Overflow to it's normal height. Hop in the Volvo and take it for a 30 mile ride.
I'm not a fan of this stuff but I have a FORD Explorer that is a nightmare with Intake Manifold gasket issues. The torque on the manifold bolts is so low and the bolt pattern is crappy...After a short time of doing the job...it leaks again. This stuff has been a grteat help for that.
Good luck
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me

If your radiator leak is in a side tank inlet or outlet, STOP and replace the radiator ASAP. In this instance, a failure will cook your engine. They tend to break suddenly.

Original radiator? If so, it's time to replace it. If it's been replaced, where's the leak? If it's in the metal, it's repairable. If it's in the endtanks and they're plastic, it's trash.
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While I would never deliberately mislead anyone, take into consideration that any information and advice provided was at no cost to you.

There are a few products out there like Bars Leak and Alumaseal, none of which I recommend unless you are stranded and then only so you can get home and stuff a new radiator in it. I have a tube of the stuff in with the jumper cables and spare relay assortment in my older cars. I recommend you put a new radiator and thermostat in it and be done with it. There is no cap on the radiator like you are thinking of. The cooling system cap is on top of the coolant reservoir or the expansion tank, same thing on your car. Carefully unscrew it so as to allow it to vent and add coolant there. It should be on your right fender.

Mark