You have a slow coolant leak – a few drips on the drive, occasional overheating, heater running cold. Solution – add a sealant such as Radweld, K-Seal or Barr’s leaks. WRONG! These materials will more or less permanently damage the engine, radiator and heater matrix. I think you have sprinkled magic dust and made a good car truly great. Jerry will be my daily driver through the summer and complete at least 400 miles a week. I’ll keep you posted… Mr A.T., Oxon, XJS Upgrade

I am absolutely thrilled with the new gearbox and transmission. The inside of the car is a real joy too and lovely to live with. I was also pleasantly surprised at the number of appreciative looks, waves, hoots, and comments during the journey eg is that really an A reg?… Well done. Mr M.D., Andorra, XJ6 Upgrade Before you attempt to fix a leaking radiator, you’ll want to be sure that that’s what the problem is. Here are the common signs that your car radiator is leaking: With a serious leak, no amount of sealant is going to fix it, so we’re only talking about minor, persistent leaks – and there is only one right way of dealing with it. Replace the offending part.So, what do you do if you have a cooling leak? Replace the leaking part – usually a hose. In an emergency one can bind up a hose dribble, and can ignore a minor leak from the radiator provided you keep topping the coolant up when the low coolant light comes on or there are signs of overheating. A car radiator leak is the most common sign that you need to fix your radiator, where you may see puddles underneath your car when it’s parked. If this is the case then you need to get the right car radiator parts to fix the damage, or replace the whole car radiator. Car radiator sealer Once solidified the material cannot be washed away or, as far as we know, dissolved in anything. It becomes a clay-like pudding which can only be scooped out by hand having removed the cylinder head(s). Physical force with a water hose can dislodge the heater matrix clogging, but if there’s any of the material left in the system it will simply clog up again.

Pour the entire bottle into the cooling system via the radiator filler cap - this is a pressurized cap found near the top of the radiator. It’s often labelled on newer cars, but if you’re unsure, your owner’s manual will tell you where to find it. If your radiator is completely closed off and has a through-flow system, you can add the sealant via the coolant expansion tank. The Wynn's Radiator Stop Leak - 325 ml is a sealing product to stop leaks in the radiator, ventilation system and head gaskets. It's compatible with all anti-freezes and coolants. It is formulated to avoid the clogging of radiator waterways and temperature sensors. Features & Benefits: Important: Always ensure that your engine is cool before working on the cooling system. Serious injury can occur.Simple to use - There is no need to drain and flush the cooling system before use; Coolant seal mixes with all types of antifreeze.