Rail out and ready to clean up for reinstallation. You can see where it had been weeping the red coolant.



Just below the left coolant flange is the oil filter consul mounting pad. I've stuffed some paper towel in the opening to avoid getting debris in there as I clean the coolant flanges of old gasket sealant. To the right is the boss for the oil pressure switch that I removed to make a bit of space for my socket handle. And yes I fixed that weepy throttle body heater hose at the top of the photo while I was under there too!



Like many XJ40/X300 owners I had been putting off replacing the hose that connects the coolant rail to the back of the water pump. Consequently it had gained the name of the "ba_stard" hose or the "devils drain" (Actually I just made that last name up but this is my post so I can do things like that!) on the forums

It wasn't so much replacing the hose that I feared, more getting access to the coolant rail that is located underneath the inlet manifold to clean the corrosion off the spigot so I could get a leak free connection with the hose.

All the Google searches I'd done indicated that to truly get access to clean the spigot would entail removing the inlet manifold. The last forum post I saw had the owner ratchet strapping the intake manifold to a wall to hold it up and away from the side of the block!

So I bought a replacement hose and a intake manifold gasket and put them away for the day when I had nothing better to do. But there was always a little voice saying "You're going to have to bite the bullet sooner or later".

Yesterday I had the front of the car up on ramps replacing the low pressure hose on the steering rack when I noticed I could probably access the 4 coolant rail flange bolts if I removed the oil filter and the filter consul. (Jaguar call this the "Oil cooler adaptor" and "oil filter head"). The consul is held to the engine block by only 4 bolts. That was a much more attractive option for me.

So I got stuck into it and guess what, it worked!

I was able to remove and replace the coolant rail with the new hose attached.

Only unforeseen work I had to do is remove the oil pressure switch on the side of the block to make room to turn my ratchet and to remove the MAF sensor and bellows to the throttle body to enable me to reach under the intake manifold to guide the hose onto the back of the water pump. Both a five minute job and much easier than the alternative.

Only warning I can give is that the clearance between the top bolts on the rail and the intake manifold plenum is not huge so if you have hands the size of dinner plates, you may struggle to get the bolts started when reassembling.

Oh, and if you don't like cutting gaskets, you may wish to buy them beforehand. Two for the oil cooler adaptor and one each for the coolant rail flanges.

 

And if you haven't replaced the O-rings in the oil cooler adaptor yet, suggest you do that as well while it's apart and easy to get to.

https://www.sngbarratt.com/us/#!/Eng....2/4.0%20LITRE

 

If the water rail gaskets are NOT leaking, why would you remove the rail??

I just slice the hose with a razor, remove it and clean the aluminum pipe ends, then slide the new on in place.

The new hose is quite flexible.

The clamps can usually be accessed through the manifold.

Never needed to remove the manifold but if I do remove it I always replace the hose.

bob

 

Hi Bob,

Unfortunately I haven't been as lucky as you have with regard the cleaning the spigot ends. Mine have all been heavy corroded with pitting and a build up of a white "salt like" substance that has taken some effort to remove. Where I haven't carefully prepared the joint I've experienced further leaks. To prepare for a leak free joint I have had to scrape, file and finish with a wire brush to get the spigots back to an acceptable condition.

Since the rail spigot is in close proximity to the block there is insufficient room to restore the spigot easily without removing the rail. Although I do acknowledge some have left the rail in-situ and used strips of emery cloth to clean theirs

The point of my post is that if the spigot needs to be cleaned there is a very viable and I think an easier alternative to having to remove the intake manifold to get access to the rail.



Regards
Peter

 

Corrosion will be the determining factor!!!!

bob

 

Peter, congrats being able to renew the water rail gaskets without removing the intake! THAT's the real news in your post. I had fairly significant corrosion on both ends of the b*st*rd hose and successfully renewed it (several times, actually) without terribly much fuss. So I agree with Bob that if the rail gaskets don't leak...don't mess with 'em! Also sound advice on changing the oil cooler bypass o rings while you are in there.

https://www.jaguarforums.com/forum/x...enewal-101914/

Clearly, the replacement that fails within the first year is an easier job than replacing the original that has been on for 20 years! My original was almost the texture of hard-plastic and even cutting it off as Bob advises was a challenge. And besides, on the second go-round, you don't have the corrosion-cleanup problem as with the first replacement. I believe I've now installed five (5!) b*st*rd hoses on 2 cars. First time on each was pre-emptive - wasn't leaking but old and I was in the area....next two due to failure of the "new" hose between 6 mo. and 2 yrs, and the last one, pre-emptive again during water rail-gasket renewal. (Learned this from my first water rail gasket renewal, when the not very old b*st*rd hose failed shortly after getting it all back together!
Even though Bob advised me that at least on the XJ-40, he thought the rail could be accessed from beneath without disturbing the manifold, I couldn't see it. To be fair, I wasn't keen to get underneath and roll around in the leaking coolant to make a thorough inspection. However, as I alluded to in another thread somewhere here, at the time, I had a near identical 96 that wasn't leaking,(well....not leaking coolant, anyway....it had a pretty voluminous oil leak from a bodged sump drain modification, but I had a catch-pan for that) had the front end elevated, and had portions of the inlet air path removed, and from inspecting it, I couldn't see a way to do it.

 

Thanks aholbro1 for your comments. I have found your informative posts and pictures a very useful aid to my first Jaguar ownership.

I've never owned a car that has leaked so much from so many locations but I think I've finally got them all nailed now!

 

Although a success here I wouldn't necessary recommend this method to everyone, purely because the 4 bolts that hold that water rail to the block are known well for breaking. If it doesn't leak, best not to touch them, I've seen plenty 40s and 300s with these bolts holding up water rail broken on first turn and you do not want that to happen on your car, replacing ba$tard hose would suddenly be a walk in the park compared to that scenario.

 

Good point, Katar and a timely reminder that for most re-assembly operations, anti-seize is your good and faithful friend!

 

Great post, Peter!

Thank you for sharing your accomplishment! I've never tried your method because like aholbro1 I've looked at things from underneath and felt it would be so awkward and cumbersome that it was just a whole lot easier to just disconnect the intake manifold and tie it back for access. I seems like it should be difficult and time-consuming, but it really isn't, and doing so gives lots of access to so many common coolant and oil leak points that I've always felt it was worth the time and effort. But the next time I'm servicing a car that only has a coolant leak from that hose and not the rail, I may consider trying your method.

Cheers,

Don

 

Hi Katar,
While the "let sleeping dogs lie" approach may suit some, I would be worried if I had some critical fasteners on my car that were so corroded that there was a risk of failure. I'd want them to fail in my driveway when I'm working on my car, not on the side of the road as I do cover some pretty isolated country routinely.

If I had any concerns about the integrity of the water rail bolts I would have removed the inlet manifold like everyone else does and used heat and other techniques to remove the bolts. However as you can see from the photo of the engine block and my previous experience with disassembly of the water pump for example, corrosion isn't a particular problem and the bolts came out easily as expected and only displayed moderate corrosion and some limited pitting just below the head. However as a precaution I did replacement them with new fasteners, including a liberal coating of anti-seize.

I'm pleased this thread has generated some discussion and hopefully helped a fellow X300 owner in the future. The worst thing is when you post something AND NO ONE RESPONDS! :-)

 

Problem here is that you will normally not see if these bolts are corroded there, until you remove them and that's when it's usually too late, if you leave them undisturbed they will be fine and will not fail. This applies to even mint cars, where they look perfect and will be of course much worse if the gasket is past its best and when it's occasionally letting some coolant past it. Even a tiny amount of coolant which you will never notice and dissimilar metals and that's the end of them
If doing this your way I would strongly advise to use some heat on them first, just to give them a better chance to come out in one piece and definitely replace them afterwards.

You could probably judge your chances by the state of the car, yours looks great overall and you were lucky but I'm not sure I'd risk it on my own or customer car unless I had to or the customer was well aware how this could potentially end, that's all.

 

Echoing Katar's sentiments and adding that late (mine) and some not so late XJ40's did not have water rail gaskets fitted at the factory, just silicone. Presumably this was a Ford cost-cutting measure. The gaskets were re-introduced for the X300's however.

Any slight seepage from the rail ports into the bolt holes invariably causes electrolysis corroding the bolts into the block. Removing the bolts can be problematic resulting in a high percentage of bolts shearing off.

When I removed the water rail, one of my rail bolts snapped lodged in the block, balling up the aluminum threads and fusing itself in place. This bolt couldn't even screw out after welding a nut onto it - thread was non-existent. It had to be drilled out and helicoiled, but not before a severe teardown to get access to it.

Anyway, just my experience - If the rail isn't leaking, I'd leave it alone ..the hose ain't that difficult to swap on the XJ40 if you remove the air pump - and on cars without air pumps, not really a problem at all.

Larry

 

Even if no one responds this year, you can rest assured that this post will help someone some day.

I find it useful to post my progress and findings on this forum, if only to archive some of the details that may prove useful in the future. For instance, do you know what kind of gaskets you will need for the oil cooler lines? I forget, if I only knew where to find that info.....

https://www.jaguarforums.com/forum/x...l-pics-160138/

I'm post #12!