Definitely do the thermostat too whilst you are under there. Its a right PIA as there isn't quite enough elbow and arm room when you are lying on your back. Dunno if there actually is space to slide things in with the thermostat attached and pipes fitted but after my previous battle thats what I intend to try when the radiator goes. Still original on a year 2000 car so can't be much longer for this world. Maybe put it on next years preventative maintenance list.

There may be an issue with hose sizes. Back in 2015 I got a full set of water hoses from DLS whilst chasing small water leaks. Its looking as if some are slightly too large internal diameter. Top hose has the very tiniest weep from the end where it fits the radiator and inlet hose onto water pump inlet had a more significant leak. Both became visible when the car was running stationry during the aircon refill process. Top hose has spring clip clamp as supplied with it so I can't tighten it up. Not happy with screw types on plastic rads anyway as the forces aren't quite even and temptation is to over tighten. Water pump hose was so slack on the water pump stub that coolant poured out when I loosened the worm drive clip to re-adjust and re-tighten. Pulled up about as much as I dare now. Looks OK so far. I fitted the hose after re-doing the front cover and water-pump gaskets but before re-fitting viscous fan, serpentine belt and belt tensioner. Easy to get on the hose clamp screw that way but my chosen position made it virtually impossible to get at the screw with everything in place. Fortunately a combined hex head and slot type or I'd never have got at it. Magnet on a stick essential for fishing the spanner out of the bottom of the radiator cowl. Twice!

Clive

Not fancying mail order on such a relatively delicate component and wanting the security of local purchase for easy return if it wasn't up to snuff I paid the extra and got a Hella "OEM" condenser from EuroCar Parts. Possibly not the best move as brackets didn't line up properly making it a bear to fit. Worked in the end tho' so worth the effort.

Drier unions on mine were immobile until I heated them up. Should have shifted the air suspension pipe first as I melted a small hole in it and let the gremlins in. Very difficult to see whats going on in that area hence the big boo-boo. Thin wall alloy union nuts are very easily distorted so leaning on the spanners or mole gripping is not effective. Restricted space meant I need three spanners out of my collection to undo the unions as the various bends and angles weren't quite right. Finally christened the stubby combination set I picked up "that will be useful" 20 odd years back. If only there had been about 10 degrees more offset angle on the open end that one spanner would have done it all.

Clive

Green-oval-nut

I've just given up Lynx and joined the Nanocom club so maybe we could do a deal. I'm fairly sure it does everything on the ABS, not sure what comes up for traction faults. I could fire things up over the weekend and check but mine is a year 2000 car so significantly different to yours.

Where are you located? I'm in East Sussex.

Original Lynx needs a laptop to run on. As I recall matters installation is a bit of a fiddle and relies on the ODB port working correctly. I'm not sure how tricky it is to transfer to another computer. I don't really want to loose the Toughbook its currently running on. For something like this I'd be a darn sight happier with a physical meet, greet and successfully works verification before doing the money thing. In all fairness it does work fairly well and pretty much does what it says on the tin. Which, unfortunately isn't always what you thought it said. Also prone to dump you in the "WTH" kitty litter if you don't really understand the operating interface. One nasty is that it will let you deflate the air suspension and lock it into transport mode but can't unlock it so the car comes back up again. Free version of EAS Unlock sorts that but need to make up a lead! Essential accessory if you ever want to use Lynx to let the suspension down.

Last Update was version 2.6.2 back in February 2015. Nothing since despite a list of promises on the Britpart site that have now disappeared. For example rather incomplete on the HEVAC side. Can't test actuators or read settings properly. Appears to be abandonware now as the Evolution version looks to have a few more features including HEVAC actuator testing.

No technical back-up or assistance. Zilch. Nada. Not at all. No one at BritPart will talk to you, answer e-mails or even acknowledge that they sell the darn thing. Except. Nice helpline for registering the device so you can actually use it. Run by third party, nice guys on the phone when I've talked to them but even they can't get hold of BritPart if there is a problem!

Bottom line with Lynx it is what it is, does what it does and thats your lot.

As I understand it Hawkeye uses the same basic software.

Clive

Gilbertd wrote:

I'd suggest getting a stud kit for when you put it back together. The overheat could have stressed the threads in the block and the studs will put less strain on them than stretch bolts.

Not sure about that.

As I understand it the thing about stretch bolts is that they have a near flat section in the yield curve between the end of normal elastic deformation and the ultimate tensile strength point beyond which fracture occurs. Once you have the bolt torqued down enough and stretched enough to get onto the near flat part of the curve the bolt can be stretched a bit more with very little change in applied force. Until you run out of the near flat region. So when the engine warms up, so the alloy block and head expands more than the steel bolt or stud making them a bit longer, the stretch bolt puts very little more force on the head whilst the non-stretch stud should still be in the elastic region so stretching it applies rather more force. If the engine overheats the differential expansion between the alloy and the steel bolt or stud will be greater so the plain stud applies still more force whilst the stretch bolt is still on the near flat section of the curve so doesn't pull much harder.

Flip side is that the stud is working in its elastic region so it recovers to its original length when things cool down and the force applied remains the same for any given temperature. In contrast a stretch bolt has already yielded when it was installed so it now stays stretched at the extra length produced by the expansion of the overheating block. The stretch bolt is now permanently longer reducing the force on head and gasket at all lower temperatures. Hence stretch bolts have to be replaced if an engine has overheated even if the gasket seems to be holding.

Thread pull out solely due to overheating isn't a worry. If they pull out you have a pre-existing problem. A pretty major one at that. The tensile forces are transferred quite close to the top of the female thread. General rule of thumb is that an engagement depth of twice the depth of a standard nut will be more than enough to snap any over torqued bolt or stud pretty much where it enters the female thread for any reasonable combination of materials. Counter intuitively turning the bolt or stud shank diameter down to the thread core depth actually makes it "stronger" (as in harder to snap) than leaving it full diameter as it improves the stress distribution. Prof. J.E.Gordon illustrates this nicely in his book "Structures, or why things don't fall down" with a stress distribution plot superimposed on a drawing of a thrush trying to pull a worm out of the ground demonstrating that its no harder for the early bird to catch a long worm as it is for it to catch a short one. Has to pull for longer tho'. (Old book now but that, and its companion "The New Science of Strong Materials" are still about the best introduction to such things for the scientifically or engineering inclined reader.)

One day I shall find time to run through the maths on this stuff so sort out exactly whats going on with studs, bolts et al both stretch and non stretch. Too much variation in expert and common opinion. Week or two full time should do it!

Clive

Well thats turned out odd. Not used the UV stuff yet as leak has finally got big enough to see after running the engine during the air-con re-gas process. Appears to be coming from where the hose connects to the water pump inlet. Hose clip seemed tight but I've repositioned it and retightened it. Maybe that will have some effect.

Was surprised to get a steady stream of water out of the joint when the clip was loose. Sort of thing you'd expect if the hose is too large in diameter. Changed all the under bonnet hoses a couple of years back with OEM specification ones from a reputable supplier so should have been right size.

Clive

Thats the sort of thing I expect to be looking for. Might be getting easier tho' as last couple of journeys its been loosing a bit more coolant. We shall see.

Clive

Thanks for that recommendation. Hit the buy it now button on a dye & torch deal. Should be here by the weekend and hopefully I'll see some evidence.

Know all about the difficulty of cleaning out K-seal and the other jollops.

Clive

Been nooging around a minor cold engine coolant loss for the last 4 years or so. Takes around 20 to 30 or so starts to loose a pint. Pretty sure the beast came with sealer jollop in the system when I got it as the problem only got noticeable after I pulled things out to fix the front crankshaft oil seal. Obviously fitted new hoses whilst the system was empty. Loads of Hermatite on the water pump and front cover gaskets suggesting that Bodgitt & Bend Garages Inc had been inside and given up. Water pump looked to be a decent quality replacement not original. Periodically one of the usual under bonnet leak suspects gets enthusiastic enough to leave visible traces and gets fixed after which the loss drops off for a while. No evidence of heater matrix O ring leaks.

So do I go (nearly) nuclear by doing the heater O rings and fitting new radiator, thermostat and water pump or do I just throw in the bottle of K-Seal I got given by a mate with a guilty conscience over too many little freebie jobs. Main temptation is that the K-Seal is free and quick! Being honest its only the heater O ring hassle that is putting me off the nearly nuclear option.

Car is a model year 2000 4.0 HSE with 88,000 on the clock.

Clive

Inserting the stud hand tight then torquing from the top contradicts all the advice given when I was working for MoD. There it was always said that the stud insertion torque should always be greater than the nut torque so the stud becomes a rigid part of the assembly. The sliding friction in the threads and under the nuts is a significant and very variable consumer of the torque applied. Two lots of initially loose threads tightening up together aren't going to help get consistent tension across all the studs. Not to mention wind-up in the stud itself as the nut tightens up and gets enough grip on the stud to twist the bottom a bit tighter too. That wind up will relax over a few warm-up cool down cycles.

Such issues are why stretch bolts were invented. The whole point with those being that the lengthwise yield curve is long and well controlled so adding a defined extra fraction of a turn from an initial torque setting low enough that bolt to bolt variation in frictional effects don't significantly alter the starting tension. Stretch bolts grow considerably more lengthwise than a normal bolt of similar diameter but have most of the same strength in twist so they don't suffer greatly from wind-up. For the best part of a decade I used to get sent data on the various weird bolts and fasteners used in big structural jobs with integrated torque and stretch measurement capabilities. Absolute zero relevance to my job but interesting, and a bit scary in the maths. I guess you really don't want the bolts falling out of a bridge, pylon or skyscraper.

No reason why studs couldn't be effectively re-engineered into the Rover V8 for performance at least as good as the best standard stretch bolts can do. But to me that leaflet is pretty conclusive indication that ARP aren't it.

Clive

Worth keeping a suitably sized transparent / translucent plastic box about the place to work in when "nail bomb potential" items have to be disassembled. I started out with the big ice cream tubs but now tend to overkill with one of the bigger, but not the biggest, ones from the bargain place. Probably something like 30" x 18" x 18". Bought to hold certain stuff thats easy to empty out when needed for other duties so it gets used. One day I shall make a dooby to hold a small vice securely. Gotta find a good enough ball joint pivoting type vice at the right price point first tho'.

Agree with the switch cleaner usually fixes it opinion.

Clive

Unless you know its had new oil recently drain the box, drop the pan, clean and refill. Assuming no suspicious bits lying in the pan or seriously horrible looking transmission fluid coming out. Although its a relatively simple autobox by modern standards its still much more sensitive to fluid quality than the old style ones. So changing oil may be enough to sort it.

Personally I figure 50,000 miles or so is quite enough for any single fill of automatic transmission fluid. Especially as only around 2/3 rds comes out. Whatever the OK for life label says. Cynical moi figures its quite true to say the modern vision that fluid lasts for the life of the box is quite true given that the box goes bang when the fluid wears out. Which probably isn't quite what the PR and manual writing guys meant. but the her-ladyship runs a T6 L322 (and drives it like its a Hayabusa!).

American shade tree rebuild experience is more about old style all hydraulic boxes, Torqueflights et al, than the modern uber-electronic breed. If you have adequate measuring gear you really can do a proper rebuild in t'shed. Almost all the wearing parts are straightforward mechanical. But then, with a Bristol 603 sitting out front waiting for me to get up enthusiasm to finish de-bodging the body side, I like Torqueflights.

Clive

Seems to depend on your supplier. I got my Dunlops at a very good price, almost 4 for price of 2, but had to order pins separately. Check.

Clive

Ha. The power of the Forum. Post up a question and things start behaving.

Did the contact cleaner thing when all this started. Nearly automatic reaction to reach for the contact cleaner can when electrics troubles are possible.

Up at normal height this morning confirming no serious air leaks, if any. As expected with the ex-LandyAir valve block. Pressure switch resistance this morning was nominal zero so switch appears to be working and tank up to pressure. Usual self levelling dance on start up. Compressor ran for maybe a minute followed by the usual solenoid chunterings and exhaust air puff. Tank probably stayed full overnight. After another minute or so the compressor restarted and ran for about two minutes followed by the usual solenoid chunter and exhaust puff before shutting down. No compressor restart within 5 minutes so it was probably properly shut down.

Put it down to access height and bought it back up to loose some air. Compressor ran for about 2 minutes before stopping. A bit long I felt but not unreasonable. After a short pause following usual the solenoid chuntering and exhaust puff the compressor started up again and ran for a further two minutes before shutting down properly.

Still leaning towards an iffy or sticky pressure switch but same fault on two valve blocks does suggest a car related issue. Same why both problem if its a bad driver pack. I suppose it could be switch on one and driver pack on the other.

Anyway seems to be working acceptably for now. I hate these "didn't understand the problem, not sure if its really fixed" things.

Thanks

Clive

My EAS system has become somewhat ambivalent about turning the compressor off when everything is up to pressure. Takes a short 5 minutes to come up to pressure from all empty so at least I got the compressor rebuild right. Once its up to pressure you get the usual solenoid clicks, small puff from the exhaust, short pause then the compressor runs up again for, usually, a short minute before repeating the cycle. Pause after exhaust puff and compressor run time vary rather pause is always less than a minute, run time sometimes goes over a minute. Sometimes it decides to work normally after an indeterminate number of short run cycles, sometimes it carries on for the whole journey. Occasionally you get a very long discharge from the exhaust suggesting that sometimes it goes well over pressure. Fortunately I've not been out and about much over the winter so its not been a major worry but really need to get it sorted now the wether has turned. I have two valve blocks both of which exhibit the same behaviour. One from LandyAir and my old one which I rebuilt.

Had another go at it today and with the ex-LandyAir valve block it was short-cycling about 3 to 5 times after height adjustment before settling down. The Lynx diagnostics says pressure switch normal during pump up and short cycling and pressure switch low once the compressor is properly stopped. Which is right. The other valve block just keeps short cycling for as long as I was prepared to run things, 10 minutes or so.

Pressure switch is the obvious cause of the problem. But two bad ones seems a bit unlikely. Especially as my valve block worked fine before I fixed it!

Clive

Hafta get my hands on some worn ones and see what can be done about making and fitting new cones then. Its not rocket science, just has to be turned smooth and true. Sorting out how to ensure that it all goes back together is probably a bigger issue. Maybe stainless steel would wear better than brass as being harder.

Deterioration is due to the itsy bitsy bits of brass that are worn off over time by the O ring rubbing on the cone becoming embedded in the O ring surface acting as a sort of grinding block. Once wear starts it just keeps getting worse due to the bits that come off hanging around to grind more off.

Clive

Looks like the seal assembly spun up, tried to walk forward and tore itself apart. Coolant everywhere suggests the seal was failing for a few miles. It takes a while to empty out a reservoir full through the weep hole at operating pressure. If a seal fails from wear in the usual manner you have plenty of time to fix but if it spins up or the body fractures it rips itself apart very quickly. Assuming seal is common style something like this : http://www.agcoauto.com/content/images/cooling/water_pump_cross_section.jpg there is a good chance the mating ring and seal bit are still on the pump shaft and the sheet metal body has just fractured at the back letting the spring and other innards work forwards over the primary seal.

Clive

Wonder what the possibilities are for re-doing the seating in the block? Well worn in this case translates to about 3/8 of not very much actual material wear and there is plenty of free movement on the springs so taking a gnats nubbin or two out ought not to alter the seating pressure enough to stop it working fine. Heck standard model engineer practice with leaky valve seats on their baby (and not so baby) steam locos is to sit a ball bearing on said seat and whack it with a hammer. Said to work for both steel ball and O ring types.

If you have decent machine shop facilities for small parts re-making the valve cones after modifying the design of the unit so it can be put back together looks to be no great issue. Just fiddly. I could do it if I had to, even make a new block from scratch if really pushed, but it all seems more trouble than is worth. That said I've not taken a good look at the valve units so it might be rather easier than I think.

Clive

Ferryman wrote:

Reasonable? The LR price for RVH100030 (valveblock only) is €1450.- ex VAT
One might expect something for that money.

Wouldn't have been anything like that price in bulk to LR ready to bolt on as the car comes down the production line. Parts have always carried a monster mark up relative to actual cost as part of a vehicle. Always used to be reckoned that it would cost you around 4 times as much to build a vehicle from parts as it would to buy. Thats DIY with no labor costs, no factory overheads no yadda yadda to pay either. Just dealer mark-up. Wild guess is ex-factory from whoever makes them is £300-£600 range for small batches. Equivalent in series production price could well have been under half that. Given that its obsolete technology and small market, can't see they would sell many at that price. Of course you do have to factor in the LR "hello Mr Parts Customer, here is your green box now turn round and bend over" bit! LR direct show around half that price for pattern or 2/3 rds for OEM in different colour box which isn't stupidly shabby considering what folk have to pay for similarly complex parts for vehicles that are in production. In many ways we P38 pilots are spoilt because so many parts are flat out cheap by modern standards. Certainly what folk are paying for bits on ordinary VW, Fiat, Renault, Honda and the like scare me.

Still be interesting to see what a functional equivalent from modern standard units would come out at?

Clive

The brass is the hard material in this case so thats what wears. Might well be better material options. At a price. Usual automotive cost-material-design compromise I imagine. Whole valve block is a fairly standard way of doing such control for its era but the usual industrial rated way of doing things would have been too expensive so i imagine the engineers had to work hard to get the price down to something reasonable. Those sort of compromises tend to bite after 10 or 15 years.

Personally I'd look for a screw in valve with fully threaded housing rather than modifying one to be trapped by an O ring. Looks easy enough to modify the hole size and tap appropriately.

Wonder if it would be practical to duplicate the whole unit with modern, miniature, " join the blocks together" style electro-pneumatic parts. Pressure might be an issue as many of the less expensive ones top out under 100 psi. Distributor price for that sort of valve seems to be of the order of £30 to £50 a pop which will be too much but careful direct from China shopping might make it work. Order of £250 for all new, industrial quality, drop in replacement would certainly attract me should I have more problems.

Clive

Thanks for the link Sloth. Looks a likely cause for mine too.

Clive