hmmmm I may check that out too.... if yes then I will ave effectively replaced the entire cooling system minus the heater core lol when replacing pump I second guessed that lower hose too... felt soft but I felt spring in there but I also thought... you know, when I put this back together, this is going to be the part I need to replace lol in fact though all the other hoses dead need renewed and water pump was time too and also radiator... when I bought it for the first few days learning the truck I had high temps...and posted a few years ago with my first experience with my disco... upon learning of the UG I then knew what was up.. I was VERY lucky it never overheated but it was close... at least in my possession... I knew it and parked it.... it was bad thermostat... all settled down when I replaced and flushed and went to green...but for a short time... then upper hose burst... fixed... then radiator went... replaced... then water pump leaked.. replaced ( it was probably still working but didn't take a chance ) then temps never really got as low as I wanted to see... highway around 197 and around town 203... probably perfect but I worried so put in motorad 180.. temps same but I thought maybe I had a cheap after market one so ordered another of the version 2 of the motorad 180 and heard it was allot better... then now since then.. temps have creeped up.. I thought hmm viscus clutch fan... changed it out... same issue... so then I installed the newer 180 just to see and bled it correctly... have tested everywhere lol good experience with that now... anyway.. BAM now its running hot... I think the thermostat has failed... I just ordered the INLINE mod parts since that is what I planned on doing eventually anyway regardless... I'm in south florida and we have 1 day under 40deg and about 3 days at 40deg per year the rest between 78-95... lol i have several fan shrouds I picked up cheap at salvage so If I decide to go back I have a replacement to make it look new i will replace all the hoses with new now... having very limited time to work on disco, its hard to spend much time teching so when I can I ask! ))))) and when I have time i diagnose lol overall I LOVE MY DISCO and only way Id replace it is for a Defender 90 or another disco lol I may pick up an older D1 for a song and a dance and convert it to a soft top! ok off my soapbox now lol

 

one thing I did notice today while driving is... if Im in acceleration my temps drop... but when cruising they climb to 210-212 and at idle around same.. occasionally 215 but usually goes back down to 210-212.. and on highway maybe 208-210... but again if accelerating Im assuming the pressure is overcoming the faulty spring in thermostat and opening it up to radiator where it cools down to around 203 if I can accelerate long enough it usually drops to around 206.6 ... this is strongly sounding like thermostat malfunction... anyone corroborate this? and on occasion it all of a sudden drops to normal temps...

 

Ill check that out when Im putting this back together... is seems I remember it being pretty stiff .. but will verify when I put it back on lol

 

ALL PARTS ARRIVED IN TIME! THANK YOU AMAZON! lol Ill try this in morning if I'm not too tired... have to do it and have truck working before noon so I can goto work lol

 

I just got to thinking .... when I bought this disco it was running hot! but with my UG I quickly realized this and changed to a factory thermostat and then it was just kind of normal to warmer.. 203 and 199 on highway... Ive always in back of my mind wondered about Previous Owner using the metal tube instead of the plastic OEM tube on top of radiator.. it looked strong and sturdy but it always seemed too narrow ( fit inside the normal tube.. in my ignorance of this cooling system and Discovery's in general, I discounted it thinking it was a factory setup as it seemed to fit... and as truck wasn't overheating really... however I did want to goto the lower 180 stat ( motorad) when that thermostat was finished for some extra cooling here in south florida... but it seems to be a littler worse than better... Im now wondering if.. having that top tube too narrow the old radiator (which eventually cracked and I replaced) may have been due to too much pressure building up not allowing the thermostat to open??? is this possible? I have a factory new expansion tube Im going to install in the morning and see what happens!! If this fixes problem, Ill hold off on inline mod until next round! I already have all the parts even an extra fan cover but wouldn't that be nice to be a quick fix and back enjoying cool driving!