| Author | Message | ||
     Chris Miller Prolific User Username: cjm51213 Post Number: 133 Registered: 5-2013 |
Hi Folks, I have a confluence of several projects. They are near each other and are probably best completed as one super-project. It is all engine compartment work. I need to remove and rebuild the A6 compressor as well as possibly other A/C parts, I need to restore the belt to the smog pump, and I need to address an oil leak at the valve covers. The bonnet is in the way. Am I going to be reducing problems or making problems if I remove the bonnet? This hinges on, (Geeze! Sometimes I just crack myself up!) the difficulty of restoring it to the correct alignment -- if that is easy, then it is a smart move, otherwise not. Since I've never done this, I seek the experience of anyone that has. Thanks for the help, Chris. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 894 Registered: 6-2009 |
Chris, Provided you mark the positioning of the hood/bonnet on its mounting brackets before removing it and have at least one, preferably two, able assistants for the five minutes the process takes for removal/installation, it's an easy task. This is discussed in Tee-One Topics; check the index for the issue number. I simply placed a very heavy blanket on the roof of the car and put the hood/bonnet into temporary storage up there until it needed to be put back on again. As long as you've got your original positioning marked it's really not difficult or tedious to remove and reinstall. Brian | ||
| Chris Miller Prolific User Username: cjm51213 Post Number: 134 Registered: 5-2013 |
Hi Brian, Thanks very much for the advice. Given the projects, I'm sure that removing the bonnet is probably a really good move. Thanks for the help, Chris. | ||
| Bill Coburn Moderator Username: bill_coburn Post Number: 1534 Registered: 4-2003 |
Chris/ Apart from a spanner the other vital tool is a helper, at least 5 feet tall. As Brian advises put your wife's full length Mink coat on the roof, open the bonnet, disconnect the wiring to the bonnet light - a couple of pull apart connectors and with a Shadow undo the earth strap on the underside of the bonnet up the front. With a scriber mark the positions of the hinges where they meet the bonnet. Equip both you and your helper with spanners (1/2" A/F). Put plenty of wadding or more of your wife's furs across the front of the engine compartment immediately behind the grille. If you and your helper are drunk and let the bonnet slide forward this will prevent damage to the leading edge, the bonnet's not yours. There are four bolts per hinge arranged in a square. Undo and remove the two top bolts and the inner one of the bottom row. Next both of you, standing either side of the car. place your head under the bonnet and your left hand over the leading edge. Remove the remaining bolt keeping a firm grip of the bonnet. Place the bolts in the recess of the suspension tower! Working together lift the bonnet, with your right arm take a grip of the trailing edge and extract your head. Lift the bonnet to a height above the roof of the car, walk sedately backwards together and place the panel on the Mink. Barring frozen bolts the whole operation takes10 minutes. Replacing the thing is the reverse but when first closing the bonnet do it very slowly checking all the edges for alignment. Now you see why the manual doesn't cover this operation. They wanted to save paper. | ||
| Bob uk Unregistered guest Posted From: 94.197.122.83 |
The bonnet is unwieldy and requires assistance Assuming that alignment is correct Drill 1/8 hole through hinge into bonnet frame use a short drill.that CANNOT go right through the outer panel only the The frame On assembly put 1/8 dia whatever to align bonnet to original position If the alignment is not good then just take bonnet off Lay dust sheet blanket on roof and place bonnet on roof for safety note high wind or gust could blow it off Look to see if holes are already drilled because this is a very common trick by body workers I have used this method on many car wimgs Other tricks are shallow cuts in edges for fixing datum points Or using satin black aerosol flick over the hinge before taking bolts out so you can see where the hinge was 8 bolts and washers easy job just take note of above Taking the bonnet off is normal in a shadow workshop Grease bolts You should by now realising that the car is not hard to work on and not that complicated You might want to remove the radiator for a check If the radiator feels heavy it could be sludge Also check transmission oil pipes mine were rusty and grotty I spotted mine before it leaked atf over the right hand wheel I used copper as replacement there is not a lot pressure call it less than 50 psi Last check thermostat If the thermostat bolts are tight warm engine These bolts can shear so take it easy. Copper slip on reassembling New stat is RR only (Message approved by david_gore) | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 895 Registered: 6-2009 |
Given what I now know about the UE36600, which has a 2-year "suggested" change interval and has a strong tendency to gall and stick open, and the PG58252PA, which has been known to stick shut (see this video from Lone Wolf, a well-known RR service shop in California), I would not even consider a RR thermostat for an SY or SZ car. I am the third author on an article entitled, Thermostat Issues and Selection, which was also published in Tee-One Topics, Issue 95 and in the RREC Bulletin, Issue 13-6, as part of their Spares Corner feature. I encourage people to watch the video, read the article and come to their own decisions. Brian | ||
| Chris Miller Prolific User Username: cjm51213 Post Number: 137 Registered: 5-2013 |
Hi Bob (UK), Your list of other things to check as long as I've already gone to the inconvenience of removing the bonnet, is really good. It expands the scope of my project, but I think it is worth the expansion. Thanks for the help, Chris. | ||
| Bob uk Unregistered guest Posted From: 94.197.122.87 |
Hello Chris My thermostat stayed shut a few years back no warning just a hot smell lucky I was close to home I complained to RR that the.stat had failed after only 32 years they didn't reply It is the nature of old cars start one Job and find more (Message approved by david_gore) | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 897 Registered: 6-2009 |
Bob, That's actually an unusual failure for the UE36600 'stat which far more commonly sticks open or has the lead pellets come out. That was the approximate age of the UE 'stat I replaced with the Stant, but it was still working at the time. I've only had one other car in my 36 years of driving that required even a single thermostat replacement and that was a 1996 Chrysler Sebring JXi. I'd still love to know why, but that car simply "ate" thermostats. You could count on the thermostat failing by "flying shut" while the car was in service. After this happened two times about two years apart I began replacing the thermostat on that car as preventive maintenance. All my other cars have run on their OEM thermostats for their entire lives. This is the rule, not the exception, and most manufacturers presume a "perpetual" service life on thermostats these days. Brian | ||
| gordon le feuvre Experienced User Username: triumph Post Number: 41 Registered: 7-2012 |
I have just replaced thermostat on Phantom 6 (1970) with NO obvious indication of any overheating just because temp. gauge read low. ALL overheat pellets were missing??? Car run very well apart from above, | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 898 Registered: 6-2009 |
Gordon, See the article I posted above, which includes a photo of the thermostat that had been in LRK37110 as I found it (Figure 3 on page 3). The situation was exactly like yours. I am the second owner of the car, have a pretty decent set of service records from the first owner and with the widow's permission from the dealer that serviced the car, and there's no record of the car ever having overheated. I believe that some of these lead pellets were subject to slowly "corroding" away. They certainly didn't melt out. Brian | ||
| Bob uk Unregistered guest Posted From: 94.197.122.89 |
Thinking about it it's the only stat I have seen fail shut I used to replace stats as a matter of course because they are cheap and the customers expect it I found if I went to the trouble of explaining why a stat should be ok the customer will then talk to a bar stool mechanic who will state all sorts of rubbish My jeep has 117k and 21years stat original Stats are designed to fail open (Message approved by david_gore) | ||
| Bob uk Unregistered guest Posted From: 94.197.122.89 |
That proves that the pellets work Where are the pellets now? (Message approved by david_gore) | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 899 Registered: 6-2009 |
Bob, It proves nothing of the sort. This is a failure of the thermostat if there has been no overheating and creates a situation where the car will run for long periods below optimal operating temperature since there is effectively no thermostat when all the pellets are gone. The UE36600 thermostat is the only one I know of in the world that uses lead melt-out plugs. Those were introduced because the thermostats can fail shut, though that's not as frequent as failing open. UE36600s fail open not because they are fail-safe thermostats, but because of galling. The return spring exerts less force than the wax pellet that pushes it open does. That often means that things get to the point where the spring cannot push the thermostat closed. This was an example of where Crewe was putting a band-aid on what was a bad design from the start. Brian | ||
| Bob uk Unregistered guest Posted From: 94.197.122.91 |
I see your point Brian This useful bit of info is now imbedded in my mind for future reference I have been sucking up car info for 50 years Thermostats are misunderstood by many people such as the by pass bit I found that cars are easy to fix but the owner much harder They especially men get preconceived ideas of how things work. Which are impossible to correct. Hence the many unnecessary parts I have fitted in my career And the endless rubbish in the media Some stats had jiggle pins to burp the cooling system I used to sometimes remove the pin so that water could always circulate on bigger engines this didn't effect the warm up time But small engines slower warm up Just a small 1/8 hole makes a difference which why running no stat is not good (Message approved by david_gore) | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 903 Registered: 6-2009 |
Bob uk wrote: Thermostats are misunderstood by many people such as the by pass bit I just want to explore your understanding to see if it matches mine. My understanding is that cars that use a bypass design do so to allow the car to come up to optimal operating temperature more rapidly before coolant flow to the radiator is allowed. Essentially you keep pushing coolant through on a "heating loop" until it becomes hot enough to open the thermostat. I realize that the thermostat doesn't instantly fully open, so there is a period where at least in theory some coolant would still be going through the bypass while some would be going to the radiator. I just don't know how much would go in each direction. My suspicion is that once the thermostat opens more than just the tiniest bit that the flow through the thermostat to the radiator is the path of least resistance and virtually all coolant would take that path. When I did the thermostat replacement on SRH33576 I simply put the Stant version in "as is" and it does not have either a "burping hole" or a jiggle pin and it worked fine. By the time I did the same on LRK37110 I drilled a "burping hole" and transplanted the jiggle pin from the old UE36600 thermostat to that hole. I also learned that it's a good idea to round off the bottom of the jiggle pin as more than one person has reported the thing turning sideways when the coolant is circulating and jamming the thermostat slightly open. Taking the slightest bit off the jiggle pin so that its base can't even reach the opening of the thermostat prevents this issue. I really question the need for the jiggle pin and would have no hesitation to make that small "burp hole" to allow air to escape as the system is being filled and leave it at that. The amount of coolant that can escape through that hole would be utterly insignificant as far as affecting speed of warm up in a RR/Bentley engine. Brian | ||
| Randy Roberson Prolific User Username: wascator Post Number: 251 Registered: 5-2009 |
In the bypass system, generally an amount necessary to maintain the correct engine temperature is admitted by the thermostat to the radiator; the remainder, typically the majority of the coolant, continues to circulate in the engine block, thereby bypassing the radiator. The engine desires a nice, even temperature, and best maintains this by circulating a generous amount of coolant constantly; at least quickly enough that the temperature differences between hot spots and cooler areas is minimized. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 904 Registered: 6-2009 |
Randy, That matches with the concept I have in my head. If things get "really hot" (but not overheated) my understanding is that the bypass plate on the lower end of the thermostat will eventually cover and block the bypass port when the thermostat is fully open, which is right around 210° F on our cars. I don't know how often the operating temperature would reach 210° F under typical operating conditions. I'd think that's pretty much a "hot summer day" thing where I live, but I've never checked it out with an IR thermometer. Brian | ||
| Bob uk Unregistered guest Posted From: 94.197.122.73 |
Randy, Brian Apologies for not replying I have web glitches from water in my cables buried in my garden I am pleased you have passed the exam By pass is necessary in water pump system to circulate water around the engine and heater plus the pump doesnt back up and waste power The stat closes the bypass before the stat is fully open Because the rad is bigger than really needed the stat will open a smaller amount UK in the death valley maybe different The by pass could be left open all the time in the UK But in say Dubai the bypass could lower the amount of water passing through the rad and maybe overheat Omar May know more All cars have a bypass many are open permanent Metro The metro was design from the mini Which had a small bypass hose from water pump to head. The heater valve controlled water flow The metro deleted the hose which was leak prone. The water valve for the heater was deleted and.a air blended heater fitted. This makes the heater the bypass. Putting a heater water valve would mean that when the heater is set to cold the bypass would be shut If the bypass were to be plugged on shadow then when the stat is closed and the heater turned off then the pump will maybe back up and maybe even slip the belt it cannot blow hose because the bottom of the rad is connected and not restricted, however the water flow due to wet liners is very good in a shadow and the water will rise and fall with heat and long before any serious overheating occurs.the stat would have lifted and the system would sort it self out So provided the system is clean and ha glycol and the bypass is not interfered with as some people do fit for purpose Antifreeze I fit 50 % then each year I add a litre then 5 years change flush and start again. I change in November (Message approved by david_gore) |
