Not endorsing any product here but... with that said, I have used K-Seal now for couple years ( don't even know for sure if I needed it at all in the beginning however it has performed great in the since, I have not overheated because of it... Ive also changed fluid 2 times and added a fresh bottle like Atlantic british and overland express mentioned... anyway... if I got a leak I don't know because I don't have any issues... Im am now due to replace water pump ( 100k ) and fan clutch... no RUSH of sound at starting up... here in south florida... my temps usually sit at 199 in stand still traffic and 194-195.8 on highway .... seems good... Im happy... I may do a leak test just for spits n giggles.... before K seal though I did have to replace radiator... added new K-Seal to new fluid as a stop gap measure... anyway... all dandy here so far!

 

K-Seal can work and has for me. I am 10,000 miles in. I had a minor leak off a water jacket in the back drivers side head, A drip a minute type of thing. I have noticed no sign of any leak since then. I have noticed no issue coolant blockage.

But Hell I am lazy and 14 bucks to save me a 2000 dollar job or 12 hours of my time doing heads was well worth my investment

 

ok something to point out.... I did run K Seal in my disco and I didnt really have any issues that I thought and Maybe this is or isn't an issue but its food for thought .... since then I have replaced radiator and hoses and water pump... none of those have contributed to any problem... I just had them and it was part of my 100k service... actually radiator did actually break but that was before the K seal.... come to find out my expansion tank was leaking.... now thats replaced also... when chaining everything because land was running a tiny bit warmer than what I see others getting even with the lower temp thermostat... I noticed on the return overflow line that comes form top of radiator to the expansion tank had some orange goo on it... Im suspecting my slight warmer ( nothing over 203deg in traffic south florida ) temps may be contributed to that metal tube gummed up.. I noticed when running the engine with expansion tank off I never see a strong squirt of water coming from that hose... even warmed up engine it is just a trickle... in the past when I first bought disco... I swear I remember it giving a nice squirty stream... anyway... Ill investigate this next week.... may be something people overlook especially when quitting form dexcool...

 

orange goo is usually residue of Dex cool

 

I agree... Thats ehat i think also... It may be a residual from when i replaced it with green... Its a small orific... Im going to remove that metal tube and clean...