& Distributors of


Sealing Well for 75 years - now made in New Zealand

Cooling System Sealant, Cleaner & Lubricant


Sealwel Cooling System Conditioner

1: How does SealWel work?

Simply stated, SealWel cleans, seals and lubricates the cooling system, with cleaners, sealers and lubricants included in the unique formula.

(i) A clean cooling system is easier to repair, so a cleaning process occurs first, to remove scale and rust, leaving a clean area for SealWel to make the necessary repair. Because of this cleaning action, you may notice an increasing flow of coolant in the system.

(ii) After cleaning, the leakage will begin to slow down as the exclusive SealWel formula begins to line the leak with repair material.

(iii) As more coats of repair material are formed over the site of the leak, the opening is progressively sealed.

(iv) A layer of repair material is formed over the inside of the hole, so that it is sealed from the inside, through the hole to the outside, with the exclusive plastic-like repair material.  This repair expands and contracts with changes in temperature and operating conditions.

(v) Finally, a non-oily lubricant minimises wear and tear on critical moving parts in the system such as water pumps, thermostats and heater valves.

2: What about oil-to-water leaks?

Most conventional “stop leak” products have problems dealing with this type of leak, whereas SealWel will make a fast effective repair because of its exclusive formula.

3: Will SealWel lubricate my water pump?

Yes – the formula includes a natural lubricant to reduce friction in bearings and other moving parts in the cooling system. No oil is added to SealWel.

4: Will SealWel repair a leaking head gasket?

Yes, provided the damage to the gasket is not so extensive that the gasket needs to be replaced.

5: Will SealWel prevent rust and corrosion?

Yes. With modern engines running extremely hot, build-up of deposits can create problems leading to the need for major repairs, or even a new engine. Regular additions of SealWel will keep your cooling system free of such deposits, helping it work at a more efficient level.

6: Can I use SealWel in a newly reconditioned engine?

Yes. Many engine rebuilders add SealWel to every engine they recondition – the minimal cost can prevent the need for expensive repairs later.

7: Will SealWel clog my radiator?

No. SealWel won't block your radiator, but if it is already blocked, flush it out first, as SealWel needs to circulate throughout the cooling system to do its work.

8: How long will SealWel last?

Thousands of litres of hot coolant pass through the cooling system of the average engine during every hour of operation. The unique components in SealWel go into suspension and stay suspended throughout their life, cleaning the system and repairing any leaks that may develop. To keep the level of sealing material at an effective level, a cube of SealWel should be added every 5-10,000km./3-6000 miles. (As a bonus, this will keep your antifreeze coolant working longer as well).

9: Do I have to drain my antifreeze before I can use SealWel?

No. The unique formula of SealWel is not affected by the presence of antifreeze or coolant fluids.

10: What do users say about SealWel?

Engine Reconditioners say:

“We have used SealWel cubes for many years in every engine we rebuild, as insurance against leaks. It works.”

 “We tested SealWel in several rebuilt engines. We were pleased with the result and now use it in all our rebuilds.”

End-users say:

“I had a leaking frost plug but thanks to SealWel I don't anymore!! You have saved me a lot of money!! Thanks. Thanks. Thanks!!! AAAA+++++"

“Actually does what you say it does! Saved me heaps in repair costs for just pennies!”

11: Is SealWel difficult to use?

No, in fact it is very easy. No measuring or weighing, just crush 1 cube per 10 litres/2.5 gallons into the filled radiator, or dissolve in hot water first. (1 cube is sufficient for most car systems.). Drive for 5km/3 miles to allow the SealWel to circulate, then top up the radiator if necessary. DONE !

Or use the new convenient SEALWEL POWDER - just add water to jar, shake to disperse, and tip into radiator.

12: What is the difference between SealWel and the Lusco Cubes and Rebuilder Cubes I used to use?

None. All 3 products use the same time-proven formula.

13: Where can I buy SealWel?

  All leading automotive parts suppliers in N.Z. carry SealWel – just ask for it by name, or give them the part no. T5101.

International distribution is currently being set up by Auto Agencies. Enquiries from suitably qualified organisations are welcomed – email


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