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Customer Questions & Answers for
Holts Holts Radweld Plus 250ml

Holts Radweld Plus seals coolant leaks in the engine block, cylinder head, radiator and hoses.
Customer Questions & Answers:
30 Questions
 | 
49 Answers
Overall Rating:
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Product Details

Questions & Answers for Holts Holts Radweld Plus 250ml

Question
I have a small leak in my car radiator is it OK to introduce a sealant product eg Radweld via the reservoir?
asked 4 years ago
by
Anonymous
on Holts Radweld Plus 250ml
3 answers
Answers
answer 1
Hi, will I had a coolant leak, and I put in it in the reservoir/header tank/coolant tank, works no problem.
Top 1000 Contributor
Top 1000 Contributor
answered 2 years, 11 months ago
by
Ceasar
 - South West London
answer 2
Yes, in fact the product advises that you can either pour directly into the radiator or the reservoir (and you may need to do both, depending on how much lost water you have in the radiator at the time.)
answered 3 years, 9 months ago
by
Tiggr
 - Bristol, UK
answer 3
Thats what i did and it worked, but i mixed it with coolant before pouring it into the tank as i heard it is less likely to clog something that way.
answered 3 years, 11 months ago
by
cordie
 - York
Question
Large Radiator Leak
I have a large leak from the bottom of my radiator that pretty much empties they system of fluid within a minute or two. Is this too big of a leak as i know you have to run the engine for a while for this stuff to work
asked 3 years, 4 months ago
by
John2502
on Holts Radweld Plus 250ml
3 answers
Answers
answer 1
This may work, I would suggest in getting two bottles, but it mix one with abit of coolant, so the system is not just full of the radweld.
Top 1000 Contributor
Top 1000 Contributor
answered 2 years, 11 months ago
by
Ceasar
 - South West London
answer 2
If the crack is really big , then answer is no.
answered 3 years ago
by
Anonymous
answer 3
This sounds as if it is too much for Radweld.
Wondarweld may be worth a try, especially if you plug the crack with steel wool (if possible) but it sound like a pretty serious leak so it may need new radiator. The best advice would be to contact your local mechanic for specialist advice.
Staff Answer
answered 3 years, 4 months ago
by
HalfordsWebTeam
Question
Will Radweld Plus cure a pinhole coolant leak in the oil cooler housing?
I have a tiny pinhole water/coolant leak in the side of the oil cooler housing. A tiny jet of water is seen when the engine is running. Will Radweld Plus solve this? And will it pour directly into the expansion tank?
Attitude to Car Maintenance: Enthusiast
How many cars: 2
Car Make: Vauxhall Vectra 2.0dti
asked 1 year, 11 months ago
by
Anonymous
 - Hull
on Holts Radweld Plus 250ml
3 answers
Answers
answer 1
yes it will solve your problem just pour the whole bottle in to your coolant system and leave the car running on idel speed for 10 to 15 mins then top up your coolant system if needed its fab stuff
Age Group: Under 25
Gender: Male
Attitude to Shopping: Quality Seeker - I'd rather spend a little extra on something if I know its going to last
Family: I'm Single - With No Children
Attitude to Car Maintenance: Enthusiast
How many cars: 1
answered 1 year, 1 month ago
by
rd1102
 - west lothian
answer 2
Yes
answered 1 year, 3 months ago
by
MGZR2004
 - Sheffield
answer 3
Hi, thanks for your interest in Holts Radweld Plus 250m.The advice from the manufacturer is that depending on the size of the hole, Radweld Plus should work. It can be poured into the expansion tank, however ensure that the engine is run for at least 15 minutes or longer, and keep the system topped up with coolant/water. If this does not stop the leak it may have to be repaired or replaced.
Staff Answer
answered 1 year, 11 months ago
by
HalfordsWebTeam
Question
will tis repair a crackeded cylinder head
I have a renault espace l reg which has just been recently diagnosed with a cracked cylinder head. Unfortunately being disabled i am very dependant on this car, will this treatment fix the problem until i get a new car?
asked 4 years, 7 months ago
by
bemmyboy
on Holts Radweld Plus 250ml
2 answers
Answers
answer 1
you could try it as a temp fix, but it all depends on how big the crack is. but may work.
Top 1000 Contributor
Top 1000 Contributor
answered 2 years, 11 months ago
by
Ceasar
 - South West London
answer 2
This depends on the nature of the crack. Minor cracks in the cooling system should be fine but it would not be able to fix major cracks affecting the fuel system.
Staff Answer
answered 4 years, 7 months ago
by
HalfordsWebTeam
Question
i have just been looking at radweld product could this product fix or temp fix a head gasket leak?
asked 4 years, 4 months ago
by
terry270
on Holts Radweld Plus 250ml
2 answers
Answers
answer 1
yes it will.
answered 3 years, 6 months ago
by
bill61130
answer 2
This isn't quite a straight forward answer, as a lot may depend on exactly what type of leak it is?

Holts Radweld Plus is the result of a project to improve the standard Holts Radweld product. By improving the formulation, it is now able to seal a wider variety of leaks within the coolant system, including those in the engine block and cylinder head areas which the standard Holts Radweld is not designed/recommended for. This is due to the super concentrated nature of the new formulation for Holts Radweld Plus. The improvements also mean it is able to seal larger holes in larger systems more effectively than other products.

Holts Radweld Plus is designed to seal coolant to air leaks in the engine block and cylinder areas. The way the product works is that it stays in a very diluted form (effectively in a liquid form so it will not block water passageways) while in the coolant system, it is circulated around until it finds the hole, then it is forced through the hole by the pressure of the system. When it is exposed to air/atmosphere on the other side and has the heat of the engine behind it, it is able to form a seal in the hole/crack. The rest of the Radweld not involved with this seal will still stay effectively in a liquid form inside the system until the system is flushed/drained. So, Radweld has the ability to stay in the system and help seal holes as and when they occur, while also helping to stop corrosion within the system.

If the head gasket leak is internal, meaning a leak from the coolant passages into the combustion chamber, or a leak between the oil and coolant systems (oil into water or water into oil), it is unlikely that Holts Radweld Plus will seal these leaks due to the vast pressure differences between the combustion chamber/cylinder heads and the coolant system.

In these internal leak cases, Holts Wondarweld would be the product recommended for use by an experienced DIY mechanic. The repair process is much more complicated: the fault would have to be diagnosed correctly in order to follow the specific instructions for each type of leak, and spark plugs would have to be removed to decompress damaged cylinders while the engine running to reduce the pressure differences between the two systems, allowing Holts Wondarweld into the leak site in order to seal it.
Staff Answer
Best Answer
answered 4 years, 4 months ago
by
HalfordsWebTeam
Question
will holts radweld plus stop my heater matrix from leaking
asked 4 years, 2 months ago
by
jonno989
 - stafford
on Holts Radweld Plus 250ml
2 answers
Answers
answer 1
yes it will it will solve all leeks in your cooling system and best of all if your cillinder head should ever crack it will fix the problem and keep your car going strong
Age Group: Under 25
Gender: Male
Attitude to Shopping: Quality Seeker - I'd rather spend a little extra on something if I know its going to last
Family: I'm Single - With No Children
Attitude to Car Maintenance: Enthusiast
How many cars: 1
answered 1 year, 1 month ago
by
rd1102
 - west lothian
answer 2
Yes Holts Radweld Plus can be used for sealing a leak within the heater matrix, provided the leak is not too severe. The way the product works is it stays in solution (basically in a liquid form) while in the coolant system, the system circulates it around and when it finds the hole it uses the pressure of the system to leak through this hole. Now when it is exposed to air/the atmosphere on the other side and it has the heat of the engine behind it, it is able to form a seal over the hole. The rest of the Radweld not involved with this seal will still stay in solution inside the system until the system is flushed/drained.
As the leak is in the heater matrix section, it is likely that you will need something like a 20-30 min drive with the cars interior cabin heaters turned on in order to open up the heater matrix side of the system and allow the Radweld solution in to find and seal the leak. If the leak is not sealed during this period, the engine may need to be run for longer as the temperature around the leak site or lack of flow of Radweld to the leak site are the causes of it not being able to seal the leak.

Of course during the drive we would recommend keeping an eye on the temperature of the system as well as the level of coolant in the system, especially if it is a severe leak which could lead to the system emptying and then overheating before Radweld is able to fix the problem.
Staff Answer
Best Answer
answered 4 years, 2 months ago
by
HalfordsWebTeam
Question
I have Volvo xc90 that has loss of compression in two cylinders and the garage think it may be down to the head gasket.
Can I use Holts Radweld Plus 250ml on my car? Do you think it might solve this problem?

Thanks
asked 4 years, 1 month ago
by
pkel
on Holts Radweld Plus 250ml
2 answers
Answers
answer 1
I don't think that work on on this problem, It sounds to me that your top end is going or gone, and you will need to rebuild the head gasket
Top 1000 Contributor
Top 1000 Contributor
answered 2 years, 11 months ago
by
Ceasar
 - South West London
answer 2
No, due to the high pressures involved in the cylinders Holts Radweld Plus 250ml would be unlikely to solve your problem.
Staff Answer
answered 4 years, 1 month ago
by
HalfordsWebTeam
Question
water loss
Peugeot 307 LX auto
loosing water but no visible leaks.
Oil still oily-not frothy as head gasket blown produces,Would any of the Rad weld type products cure this?
asked 3 years, 6 months ago
by
Anonymous
 - hatfield
on Holts Radweld Plus 250ml
2 answers
Answers
answer 1
I had the same problem oily coolant, I put this stuff in it and its worked.
Top 1000 Contributor
Top 1000 Contributor
answered 2 years, 11 months ago
by
Ceasar
 - South West London
answer 2
Its worth trying to use this product to stop the leak. However I would always recommend seaking proffessional advice to prevent long term damage to the engine.
Staff Answer
answered 3 years, 5 months ago
by
HalfordsWebTeam
Question
water loss
hi, head gasket failed and the garage repaired this, however still finding that i have to top up coolant every 300 miles to avoid overheating, as it starts reaching the red, the fan kicks in and brings it back down to 100c. no visible signs of HG failure that were present before the garage fixed approximately 5000 miles ago...would this help?
asked 3 years, 4 months ago
by
smalik
on Holts Radweld Plus 250ml
2 answers
Answers
answer 1
Did the job for me!
answered 3 years, 3 months ago
by
cliff06
 - Gateshead
answer 2
Radweld Plus is designed to solve cooling system leaks in the engine
block and cylinder areas, coolant-to-air only, so if you are not sure where
the leak is and it's "coolant to air" leak then Radweld Plus should be
able to repair it.
If you are not sure if it's internal or external leak, or where the leak
is, then Holts would recommend you should try Wondarweld, since it was
designed to permanently seal cracked cylinder blocks, internal and
external leaks in the water jacket. If you have doubts consult with a qualified specialist.
Staff Answer
answered 3 years, 4 months ago
by
HalfordsWebTeam
Question
where do i pour this
do i pour this into the expansion tank with or without collant being present in the tank ??, and how much do i pour in
Car Make: renault
asked 2 years, 9 months ago
by
Anonymous
on Holts Radweld Plus 250ml
2 answers
Answers
answer 1
Empty the full contex in to the radiator not the expansion tank.
Car Make: Bmw mini cooper
answered 2 years, 4 months ago
by
wolfblood
 - bridgend
answer 2
The 250ml bottle treats up to 21L systems. If the coolant capacity is 7L or less, use only half bottle.
Add either into the radiator or overflow reservoir (expansion tank), top up with recommended coolant if needed.
Radweld Plus is compatible with all forms of Anti-Freeze so there should be no problem with introducing it to a coolant system containing Anti-Freeze.
Staff Answer
Best Answer
answered 2 years, 9 months ago
by
HalfordsWebTeam
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