From an engineering viewpoint the early car hose routing basically follows a common practice for a beam axle rear suspension car. Hard pipe down the vehicle, intermediate flexi to an axle mount to take suspension articulation, hard pipe across the axle and short flexi to each calliper so you can service brake pads et al without disturbing connections.

Sensible if you only have one front to back line as in pre ABS days. At best inelegant when you have independent lines to each calliper.

Basic routing on the later cars is much more logical with independent hard pipe to calliper routing on each side with a single body side cross pipe. The hard pipe ends at a body mounted bracket with with the short flexi jump hoses going to the first chassis mounted bracket. Presumably these cover any possible movement between body and chassis.

Surely they can’t move that much?

Even if there is movement to handle the extra flexi and short hard pipe each side seem way overkill. Far as I can see there is no reason why the hard pipe couldn't run down onto the chassis or onto a longer body mount bracket close by and pick up a longer flexi from the calliper. Maybe an intermediate fixing for a clip to hold the longer flexi in the right run.

If I were to modify the system thats what I'd do, Kunifer down to a re-engineered version of the body bracket then braided stainless covered hose to the calliper. The braided hose would be rather longer than the standard flexi one, which seems quite short given the amount of suspension articulation it needs to cover. Or maybe ignore any possible body to chassis movement issues and do an "inverted" version of the lower jump hose bracket and pick up there. Inverted to give more spanner swing room. But still need something to tie the ABS wheel sensor cable too. Bulkhead fittings on the bracket of course. I’d rather poke Kunifer all the way up a car than braided flexi.

The anti rotation "banjo with a lump" fitting on the calliper is needed because there is only a short length of hose between the calliper banjo and the first clamp. Low end mechanics don’t unbolt hose clamps! Without the lump it would be easy for low end mechanics twist the banjo loose when removing the calliper. If you have a loose guide rather than tight clamp there is no problem.

I’m usually not shy about modifying things but elected to keep mine standard due to not understanding why things were done that way. To me the P38 falls into the same category as Soviet weapons systems in that there is usually a very good reason for “WTF did they do that!” so jumping in and changing for something apparently more logical can dump you in a world of grief.

The only reason I can think of for all the flexi pipes is to control ABS and ETC resonance effects There seems to be fairly extensive literature and respectable number of patents floating around this subject. Sharp hydraulic fluctuations can resonate up to very high localised pressures if there is no damping in the lines. Flexi pipes will provide damping, even without expansion.

The big weakness of braided hoses is that the join between hose and fitting is relatively weak in tension. The crush collet doesn’t get a particularly good grip on the slippery teflon core. It’s frequently quite easy to simply pull the hose out by hand. Especially when home made.

Clive

Great to hear that you are nearly sorted.

Concerning machining the air tank plug to take a screw shank push fit connector I have a a spare air tank so can easily rob the plug from that to modify if the matter becomes urgent for anyone. Back burner job for now.

Under seat connectors are known for loosening off and causing odd warning light issues if the seat is moved. I often push my passenger seat right forward fora bit more load space and have learned to check connectors and warning lights before filling the car up! Never a problem checked before loading but both times I got rush headed and didn't check I got the light show.

Clive

Worth remembering that, even if the pipe is carefully cut and chamfered, those push in connectors are only rated for a limited number of connection-disconnection cycles if full pressure rating is to be maintained. The O rings do get old and loose flexibility over the years too. Fine until you disturb them but old O rings may simply not manage to seal if you are unlucky.

Personally I'd not mess around with the innards of the connector. Too easy to damage the collet if you are having a a bad day. The slightest sniff of trouble on my air tank one and it gets drilled out, tapped BSP and a brand new high end connector goes on. At around a £5 for an 80 MPa rated all metal one its not worth futzing.

But I'm set up to do this. Given the plug unit seems to be no longer available mayhap I should do a couple or three for service exchange stock.

Apologies for any confusion over the types and rating of the ordinary connectors. I was thinking in terms of folk needing to do a repair somewhere on the air harness and spluttering over the £15 odd cost of the official connector, STC8580, when E-Bay offers look-a-likes for a quid or so.

Those China cheapies are rated at 0.8 MegaPascals (0.8 MPa) sounds like a lot but thats only 115 psi in real money. Too many suppliers round that up to 150 psi which they may or may not hold. For a while. Good breeds are usually 8 or 14 MP, call it 1000 or 2000 psi, which is a bit more like it. You also see them rated at 80 bar which is 1000 psi too.

Clive

I swear they bolted the air tank to that top rear mount first then built the chassis around it!

If the pipe blew out of the tank either the connector is damaged, most likely O rings inside, or the pipe is. Decent breeds of push in connectors are rated for 14 or 20 bar and won't blow out.

The cheap crappy ones, usually black body with baby blue release collars, are only rated for 150 psi. (On a clear sunny day designed for deckchair and beer.) They will blow. Heck I've had them pop on the floating air legs of an optical table at, probably 30 psi max. (£20,000 + worth of table and legs at 1996 prices and they cheap out on the connectors.) Confusingly Festo do decent 14 bar black plastic connectors with turquoise blue collars. Guess thats what the cheapies are copying. Never get caught out if you know but Joe Ordinary won't.

Wouldn't call the P38 brake bleeding procedure complicated. Follow the checklist for about an hour, job done, and remember to be gentle the first time you test the brakes. Jump on them at a sedate for first test speed and its "Ooof, clonk. Hello steering wheel, hello windscreen!". It settles a bit after the first few times, but not much. P38 brakes do sag off over the years and its easy to forget just how formidably powerful they actually are.

Thing with the P38 is that you have about 6 systems to clear. Hybrid pure hydraulic / power boosted front, power boost only rear and independent ABS on all the wheels. The ABS pump also does double duty to pressurise the power boost system. So its never going to be super simple. But it is straightforward and always works.

Clive

Having got myself back up to speed on the braking system I'd say you pretty much have to do the whole thing.

If only hydrostatic bleeding is needed the rears could be considered isolated and done on their own. Needs fluid flowing freely though so its going to be messy and you have to be pretty quick. StrageRover managed it but I reckon he was somewhat lucky.

The procedure looks a lot worse than it is. Basically painting by numbers and ticking boxes off the check list as you go. Best thing is that it works "Just like That".

Hardest part is getting at the front and rear, especially the rear, booster bleed nipples. Nice thick bit of sound deadening lying all over the top on my car. I lie on top of the engine and try to convince myself I'm left handed!

The two things I always forget is to arrange a decently bottom heavy container to take the bled fluid so it doesn't fall over and decently long length of nice soft tube to to go from nipple to jar. You will use at least a litre of fluid!

I have a slightly improved version of the factory write up on the computer somewhere and pdf of my checklist. I'll shoot them up when I've finished this pontificate.

Clive

dave3D
Yep, found the Craddock listing after I'd made mine. But I've not had much joy in trying to get stuff out of them in the past so not on my preferred suppliers list.

Two hours and a litre of DoT4 this morning got the whole system bled with excellent results. Usual hour to do the job, hour to scare up all the bits and bobs of "tools", find the cheat sheet and revise the method. Looking at my checklist sheet last time (first time actually) I did this was on 12 th October 2018. No wonder I couldn't remember how to do the job.

Brakes are better than before, and they were pretty darn good but I had done an accumulator change without bleeding afterwards. Clearly not necessary but I suspect you do loose a bit of ultimate braking oomph.

Couldn't get any flow through the pipes when I uncapped them so the StrangeRover method wasn't gonna fly.

Clive

Front goes up tomorrow then and they all get done. 3 litres of DoT 4 in stock so I may as well change the fluid whilst I'm at it.

But I shall pre-bleed the rears the StrangeRover way first. Don't like working on partially filled hydraulic systems.

Clive

Can the rear brakes be bled on their own with satisfactory results or is it best to do the whole system?

When I changed all my brake callipers couple of years back the rear flexi pipes obviously weren't coming undone so i kicked the can down the road and left them as still being functional.
The metal extension on one rear caliper pipe let go last Monday so I've been dodging the rain for the past couple of weeks of spare time getting things changed. Which included making new sheet metal brackets ANR 5918, ANR 5919 and the "flat with a slight bend one at the bottom" which, apparently has no part number. Searching the usual supplier suspects indicated that availability of ANR 5918 & 5019 appeared to be spotty with daydream prices on some suppliers.

So I drew them out and made a set of four. Drawings can be sent as a pdf if anyone wants them. Not intrinsically hard to make but something of a PIA to mark out and cut to size making for a slow job. I officially have too many toys, including a 41/64 th drill for the hose hole, so getting it done merely took longer. Cutting the blanks would have been an ideal job for the baby CNC mill I've never worked up enough enthusiasm to get going.

Further searches after the event suggests you can get ANR 5918 & 5019 for £5 - £10 each if you choose suppliers wisely but no one seems to have both.

Clive

Agree 125 nm sounds way too high.

Hafta say I didn't look at the book and just went tight, probably in the 50 nm region. Googling around it seems that 40 - 50 nm is the general range for most things. 40 on a Defender I think.

When I have a "looks too tight" issue I either go by the other fastenings list on page 14(?) of the torque values section in RAVE. If I'm feeling techie I'll use the significantly over comprehensive list out of the official BMW workshop manual for the air cooled R series twins.

Having RAVE printed out in lots of loose leaf binders with the pages in individual transparent wallets to permit handling by oily fingers is a great help with this sort of flip back'n forth issue. Two or three folders open at once is easy or I'll make up a special to the task temporary manual with all the relevant pages in one place. Re-filing is a pain tho'.

Clive

UK customs seem to charge on everything thats not from China.

My one and only experience with the GSP from the USA earlier this year was less than impressive. Expensive, slow, Stateside tracking data made no sense and I got done for duty on something that should never have attracted it. I suspect the vendor milked the system. But when its new old stock of something that makes unicorn droppings look common you are somewhat stuffed. Annoyingly the American supplier originally got it from Italy at, presumably uber low clearance prices.

Clive

Didn't you like my pretty grey paint on the radius arms?

Everything I do under a car ends up grey rather than factory black. Obvious what I've done that way and it brightens things up a bit too.

Bolts at both ends are likely to be leak down types with a longitudinal groove cut along part of the thread so any air inside can escape before the bolt comes off the end of the thread. Without a leak path the bolt can be fired off as it reaches the end of the thread. As I remember it the pipe connector end is certainly leak down. Never had the other one off.

Legal requirement on vehicle high pressure air systems I think.

Often a non standard thread to stop folks jamming a plain blanking plug from the local plumbers shop in. Hence ££ or un-obtainium for normal folk. I just measure up and make if I need such. But Clive is not normal!

For the connector end a tapped hole for the standard male BSP thread to O ring fitting adapter would be the easy way if you don't have the official thing.

I found the big issue when removing whilst lying on my back underneath was reaching the bolt heads. My collection of extension bars wasn't able to make up the "best" length to get a socket straight on without the breaker bar or ratchet fouling on something. So I ended up with a UJ in the line to get some deviation. UJ may be handy but it makes it harder to keep things straight and heaving.

Especially with those never to be sufficiently cursed integrated head'n washer bolts. Everything is tapered so the socket cant get a proper seat or gip on things and the head material is intrinsically soft with a bit of surface hardening from the forging process. So once the corners go you are stuffed.

Getting into the habit of just putting the Irwin extractors on right from the start unless I'm pretty sure that things will move.

Not the first time I've been seriously tempted to make an extension the right length by cut'n weld.

10 bar of air really isn't too bad because it generally just leaks and hisses. Not like boiling water under pressure with lethally large amounts of energy locked up in the change of state between liquid and vapour.

Clive

Looks a bit worse than mine was when Mr MoT man told me to do something about it before the next test a three or so years back.

I got me a used one which, frankly, was not noticeably better although it still had significant paint and a data label. Enjoyed(?) myself with a 2 1/2"twisted wire cup brush on the angle grinder shifting all the grot. Those brushes are very effective but need everything strapped down well or things go flying! I imagine the bigger ones can be quite lethal.

Coat of Krust rust killer, followed by two each of the Blackfriars rust resisting undercoat and grey QD90 metal paint got it looking acceptably smart without needing to faff about with the spray gun so I did a replica label to finish the job. Inkjet print & laminate. Glued on to look the part. Still got the PDF file if anyone wants it.

Shifting the old one took considerable effort and verbal encouragement. The bolts aren't easy to get at and mine were well rusted in. The new one went in with appropriately anointed stainless fixings so it will come out next time. I've no idea whether or not creative cursing about the person who last fitted something has any effect in the afterlife. But I'd rather not find out personally as my verbal assistance tends to be somewhat heavy on the creatively comprehensive side.

Best part of a fortnight elapsed time when all was done, dusted and paint hardened off.

Mr MoT man was happy which is the main thing.

My old one still sits in dry storage waiting for me to decide what to do with it. Sell, trade, gift. As is or paint first.

Clive

Silicone brake fluids were originally developed in the USA for military vehicles. Primarily to allow vehicles to be taken straight from storage and into battlefield service without a regular fluid change cycle on stored vehicles. En-mass fluid change on a battalions worth of transport before deployment being a right PIA and major league difficult on many AFVs. Lower freezing point is handy on air deployments too. Cargo aircraft get cold inside.

It has absolutely no advantages whatsoever in a normal vehicle. It may not be actively hydroscopic but it still entrains water via temperature cycling and similar drivers. Objectively it should only be used in a sealed or semi sealed system. Preferably in a pump fed system with arrangements to extract any entrained water. Our P38s would be a good candidate if fitted with a motorcycle style fexible diaphragm sealed reservoir. Theoretically motorcycle systems can safely use silicone fluids. In practice temperature cycling seems to cause water ingress through the seals and promote corrosion inside.

The Australian Army had some research done into best ways of changing from the normal issue fluid to silicone fluids. With sometimes worrisome results

"In the case of vehicle 37-971, total loss of braking effect and loss of pedal resistance was noted approximately 15 minutes after the vehicle had been returned to the garage. Next day the brakes had returned to normal with no sign of fluid loss or leakage from the system. All brake assemblies were stripped from this vehicle with the liquid contents intact and taken to MRL for disassembly and inspection. All were found to contain residues of OX(Aust.)8 despite the syringe sampling operation which had resulted in the samples to which Table 1 refers."

Full report is at (https://apps.dtic.mil/dtic/tr/fulltext/u2/a159501.pdf). Looks like the experimenters were more careful than an ordinary mechanic.

Clive

The tabs slide. Screwdriver in the opening and carefully ease them back under the trim.

Opening is usually OK but closing can be problematical because there is very little meat on that end. I borke one of mine 10 years (and lot of UV) ago. Careful on the first one wasn't careful enough. Very, very careful on the other three was.

Clive

If you fancy using Thule bars with the standard roof rails, probably the easiest fit as it just buy'n fit, do consider potential height issues.

The tops of the standard Thule bars are almost 2 metres / 78 inches off the deck in standard height setting depending on exactly where your EAS is set. High enough to be a worry with the entry restrictors for car parks round my way. I never actually scraped them but too close for comfort really. Ended up only fitting them when I needed to carry something.

Clive

The "Sports Cross bars" STC50252 mentioned by leolito are indeed very neat but you are still restricted to using as a pair due to the roof curvature. The catalogue pictures (https://knook-jaguarlandrover.nl/wp-content/uploads/2017/12/Accessoires_LR_2000_Range_Rover.pdf) show them used in centre and rear positions. Dunno if one has slightly shorter legs to fit in the centre mount letting the load ride level or if both are the same so the load rides with a slight up tilt.

I'd not care to remove and refit on a regular basis as the sliding cover over the bolt holes seems to go brittle with age and is likely to break when moved. One of mine did!

My DIY plan was to make short adapter blocks to fit on Thule bars (well actually the £20 LIDL knock offs!) which could in turn be affixed to black anodised alloy blocks permanently fitted in the standard mount recesses. Easy fitting requires the blocks to be tall enough to take bolts through the side. I didn't care fore the look of tall pimples on the roof. Bolting from the top lets them be made near enough flush with the roof. But then, like Granny Ogg and her giraffe, you need to stand on a stool to manage things.

As ever its hard work being factory neat. Can't abide obvious DIY.

Clive

I assume you don't have the longitudinal roof rails fitted.

The longitudinal rails bolt down via tapped holes attached to the roof structure. Sliding covers over them. If they have not been moved for years its easy to break the tag so good clean and squirt with your favourite "wonder-spray".

The official Land Rover cross bars can be fitted at any point along the rails. But the longitudinal rails follow the roof curvature so you need to set the cross rails roughly equidistant from front and rear if whatever you have on top is going to ride level.

Longitudinal rails are findable from breakers but not cheap. Official cross rails seem to be hens teeth rare and, usually expensive. Found my cross rails at an affordable price mainly because the seller didn't know what they were and I was feeling lucky that week! Dunno if L322 ones will fit. Design is similar but not sure if the clamp end is different.

Before I went factory i looked into making three QD cross rails picking up on small blocks bolted to the official rail mounting point. Three rails is probably better for a canoe which that sort of system will give but you are pretty much stuck with permanent pimples half inch - inch (ish) high on the roof if the system isn't going to be a right pain to fit. If you don't mind fitting from the top it can be done very neatly.

Thule bars will clamp to the longitudinal rails. Might still even have the set I used before I found the right cross rails lying around somewhere. Her-ladyship half inched them for her L322 roof tent project, then we found some proper Land Rover rails and I can't remember if my Thules ever came back. Roof tent idea died after she drove into a car park height restrictor and knocked it off. L322 died soon after in protest at being looked after by a Defender and Jeep specialist! Of somewhat questionable competence.

Clive

Just need to update the drawings to include a version with the taper roller bearing outer as the compression element. Much simpler unless you have a high end toolroom or similar machine with effective taper turning attachment.

Hopefully all done by the weekend. PM me your E-Mail and I shoot it over when finished.

Clive