Brake refurb time :D

[Scooby Jim]

I'm slowly getting nearer to the end of my rebuild of my 1972 `88.
Now comes the brakes.

I picked up a full set of V8 brakes 11 inch diameter 3 inches wide, all around
Well I have lifted them up onto my workbench to begin the process, so had a nose around.

I knew the rears were again larger than the standard rears, but my god are they more heavy duty!!
The return springs are fudging mahoooosive!! Pic sshow standard `88 caliper and shoes, and a V8 version.

Anyways when done the system will be a Servo assisted, single line setup, of twin leading shoe fronts, and single leading shoe rears, all using the 11x3 inch setup. So should be good for my little V8 `88 , with Disco diffs and these brakes it should be able to drive at normalish speeds and brake in a normalish manner.

[jerboa]

You may possibly find that you have a problem with fitting Stage 1 V8 to a SWB landy, apparently they can snatch. I'm not totally sure, but parabolic springs can help.

I never knew how much bigger they were though..!

[missingsid]

Nice size drums I also did not know how much bigger they were.

By snatching do you mean pulling to one side? If so i may be wrong but it is always going to do that as there is no anti roll bar to stop it dipping on one corner? It is always a challenge to catch my S1 if I have to perform an emergency stop as it never goes the same way twice.

Marc.

[Phil Hancock]

Exactly the same brakes as a 6 pot. BTW the rears are only 2.5" wide.

[Scooby Jim]

Cheers guys. From what I have been told and experienced with similar, was if I'd have changed just the fronts and the master, then that would be really grabby, due to the differing efficiency of front to back. By changing all the system it keeps it matched, so although there is less weight, they should work as if it was a lwb V8/6-pot.

Either way, I'll take it to a car park and do some emergency stops to get a feel of how she will react, and take it from there. The only things not being changed atm are the brake pipes, being decent copper line, but seriously considering some braided hoses.

[Snagger]

I'd be slightly worried about fitting 2.6/V8 brakes to an 88", as they might be too powerful and tend to lock up if you press the pedal too hard. The standard brakes for the vehicle should be able to lock up if the pedal is used very hard, so these could need very sparing use. I'd have recommended using standard 4-pot 109 brakes instead, but as long as you're careful, you should be alright. I'd recommend testing them on an empty road once installed to see how easy they are to lock up so yu can avoid nasty surprises later! It'd also be worth getting them tested at an MoT station and a letter or report written to confirm the installation is safe - it could save you backside legally and financially if you later have an accident.

[Scooby Jim]

I'd be slightly worried about fitting 2.6/V8 brakes to an 88", as they might be too powerful and tend to lock up if you press the pedal too hard. The standard brakes for the vehicle should be able to lock up if the pedal is used very hard, so these could need very sparing use. I'd have recommended using standard 4-pot 109 brakes instead, but as long as you're careful, you should be alright. I'd recommend testing them on an empty road once installed to see how easy they are to lock up so yu can avoid nasty surprises later! It'd also be worth getting them tested at an MoT station and a letter or report written to confirm the installation is safe - it could save you backside legally and financially if you later have an accident.

That is the plan as said above, about finding a remote location and testing them out. As for an MOT station report, it will have to go through an MOT before it can be used, so I'll get them to write something, but a test pass and brake test result should do. And tbh how many would even know the difference anyway, as its all genuine LandRover parts. Most people wouldn't even notice.

But in all seriousness, I really doubt that it would be that bad, as the only difference between a V8 109 and an 88 would be weight, and would there be that much difference?? Mine has a V8 so that's the same, I'll have to look at kerb weights, and post up the differences.

[Scooby Jim]

Using the standard figures, as all things being equal it shouldn't be too far out I'm looking at 348lb difference (approx 150kg, 24stone)

between a 88 and 109. Now with my chassis being a HD Galvanized jobbie, that should add a few extra lbs, so although they are a bit large for the 88 I think they should be fine, as with the extra efficiency, you shouldn't need to slam on to get the brakes to work.

Having upgraded brakes on road cars I know the difference they can make, but with me never having driven a Series, I should just get used to it as it will be. Same with my Disco diffs, I'll not know the difference until I do drive a bog standard series.

But time will tell I suppose, don't suppose you can fail an MOT for brakes being too efficient can you??

[Snagger]

My concerns are related to the snatching jerboa commented on - they are twin leading shoe, and so will pull them selves on to some extent with the pedal pressed in a bit. They may end up too sharp, giving too sensitive a pedal. As said, a brake swap can make a huge difference to the vehicle, but so can the 24st empty vehicle weight difference between 88 and 109V8.. LR used 11" drums on late SIIIs, essentially 109 rear brakes on the front, with 10" drums at the back. In good order, they are very effective. I can see the desire to uprate the brakes for an 88" that tows or load carries a lot, but I think a standard SIII 109 system would have better avoided over braking. Hopefully, these concerns will be unfounded, though.

As for an MoT pass being adequate for insurance purposes, it won't. The insurers must be specifically informed about any and all modifications, and an engineer's report would prevent the police or insurers pinning the blame on your brakes. In a serious accident, the vehicle would be inspected with a fine toothed comb, and it's highly likely that any mods would be picked up. That would render you uninsured if not declared, and thus personally liable for any costs or compensation of an accident. It's also good from a safety perspective to have a second set of eyes closely scrutinise a mod, rather than give a cursory MoT inspection. It's not worth the safety and financial risk.

[Retroanaconda]

When I rebuilt my 88" I put the standard 1980-onwards twin-leading shoe system on, as it would have had if it came out of the factory in 1982 rather than 1972. Nice and standard then and built to a specification that Land Rover intended. The twin-leading-shoes on the front sure make the brakes good, they anchor up really rather well. Granted it's only a 2.25 but still.

Give it a go and see what it's like, you can always change it again if you need to

[Scooby Jim]

I have never owned a non modified vehicle, all above board and certified. I have never known an insurance company ask for an engineers report when upgrading brake parts using Genuine Manufacturer parts. They have on engine replacements and conversions, and for fitting non "OEM" parts, by OEM I mean something NOT from the say Land Rover series parts bin. And even then all they wanted to see was they worked, didn't foul anything, and I had used good pipes etc, or with engines checked everything matched and the mounts were up to scratch. With the usual chassis inspections in key areas.

When I rebuilt my 88" I put the standard 1980-onwards twin-leading shoe system on, as it would have had if it came out of the factory in 1982 rather than 1972. Nice and standard then and built to a specification that Land Rover intended. The twin-leading-shoes on the front sure make the brakes good, they anchor up really rather well. Granted it's only a 2.25 but still.

Give it a go and see what it's like, you can always change it again if you need to

That's my thinking too, and as I've never driven her, I have nothing for comparison so I'll just get used to how she is. Personally would rather brakes be a bit ott, than lacking if push comes to shove!!

[Snagger]

I have never owned a non modified vehicle, all above board and certified. I have never known an insurance company ask for an engineers report when upgrading brake parts using Genuine Manufacturer parts. They have on engine replacements and conversions, and for fitting non "OEM" parts, by OEM I mean something NOT from the say Land Rover series parts bin. And even then all they wanted to see was they worked, didn't foul anything, and I had used good pipes etc, or with engines checked everything matched and the mounts were up to scratch. With the usual chassis inspections in key areas.

The insurer not asking for an engineer's report would not be a defence against a police prosecution or the insurers voiding the policy after an accident if there was any suspicion the brakes were in any way involved in the accident, be they too weak, too strong, unbalance or fail outright. My insurers didn't want a report for anything other than the engine swap, but I gave them reports for that, the axle swap (since the mounts had to be fabricated to attach coiler axles to leaf springs) and disc brake conversion. These are the legal and financial industries we're talking about - the most dishonest, weaselling nit-pickers you can find - don't give them any ammunition to hit you with further down the line!

[Phil Hancock]

LR used 11" drums on late SIIIs, essentially 109 rear brakes on the front

11" yes but they were the TLS fronts not SLS rears.

[DaveSIIA]

My experience with 11" (x2½") drums all round on a SWB IIA was that a servo made the brakes a bit fierce. Chamfering (45°) the leading edge of the front shoes made the initial bite less severe and gave a more stable balance side to side. The servo was removed as the brakes remained very sensitive to pedal loading - sort of digital, all on or all off.

The vehicle had to work for its living and was regularly heavily laden or towing a large trailer. Brake fade was never an issue.

[Scooby Jim]

My experience with 11" (x2½") drums all round on a SWB IIA was that a servo made the brakes a bit fierce. Chamfering (45°) the leading edge of the front shoes made the initial bite less severe and gave a more stable balance side to side. The servo was removed as the brakes remained very sensitive to pedal loading - sort of digital, all on or all off.

The vehicle had to work for its living and was regularly heavily laden or towing a large trailer. Brake fade was never an issue.

Cheers for that, will chamfer the leading edges.

I was thinking that too about the Servo, that if they are a bit too much then I can remove the vacuum hose lol.

But I still think that they should be fine, and I'll just have to get used to it.

[Snagger]

LR used 11" drums on late SIIIs, essentially 109 rear brakes on the front

11" yes but they were the TLS fronts not SLS rears.

Curious. Our 1980 Lightweight had 11" SLS front brakes and 10" SLS rear with dual circuits and servo. I was under the impression that the early brakes were single circuit 10", and the late brakes on 88s dual line and assisted. I must have understood tat wrongly. Then again, there were a lot of things that seemed to be changing over in 1980 that didn't all happen on the same vehicle, with all sorts of mixes of specs. This one was pre-rationalised as far as the flat flat hubs and stub axles. Presumably the later 88s had exactly the same brakes as the 109, then?

[Phil Hancock]

Curious. Our 1980 Lightweight had 11" SLS front brakes and 10" SLS rear with dual circuits and servo. I was under the impression that the early brakes were single circuit 10", and the late brakes on 88s dual line and assisted. I must have understood tat wrongly. Then again, there were a lot of things that seemed to be changing over in 1980 that didn't all happen on the same vehicle, with all sorts of mixes of specs. This one was pre-rationalised as far as the flat flat hubs and stub axles. Presumably the later 88s had exactly the same brakes as the 109, then?

It sounds like a PO has put LWB rears on the front as an upgrade, how did they perform?

Late 88" were dual line with a 109" front axle, the 10" rears were just the same as early rears but with the larger bore cylinders(88" front/109" rear).

[Snagger]

It was very good, at least until the master cylinder leaked into the servo and I had to use the servo an master I'd just removed from the 109 (Discovery brake upgrade) as a temporary fix, which resulted in much less efficiency than with the original master cylinder (the 109 components were in mint condition, being new Gen Parts fitted during its rebuild and still unblemished when transferred).

[Phil Hancock]

The difference in performance would be because the earlier dual line master cylinder fitted on 88" models has a 15/16" bore as against the same age 109" master which looked identical measuring 1" bore.

[Snagger]

Yep - I didn't know the measurements, but I did realise the sectional area of the 109 cylinder had to be bigger, creating more pedal resistance for a given brake pressure. It was only a temporary fix that was done shortly before the vehicle was sold anyway - typically it failed at Billing while on display! The new owner was informed of the change, and the original cylinder and connecting pipes were included in the sale, so that he could finish the repair. It really wasn't nice with the 109 cylinder.

[Scooby Jim]

Right back to the progress, I have now removed the brakes from the hubs and shafts. Stripped them down and thats how they have been left.

Reading your comments above, what Master cylinder should I go for with this setup??

As I was planning on keeping everything matched, so a 109 Master cylinder for the single line brake system.

Would this be ok, or would the 88 one be better from experience??

Pics from Today.

Swivels, one is really good, and one has some slight rust/pitting but both were full of oil.

Drums.

Size difference is nice, fronts on left, rears on right.

[Snagger]

You will need the 2.6/V8 master cylinder that goes with those slave units. A single circuit master would be dire. You will need servo assistance, so if you previously had single circuit brakes, you also need the pedal box assembly, servo and vacuum system from a donor vehicle (any 109 or servo assisted 88, not specific to 2.6/V8). The dual line systems have a Pressure Differential Warning Actuator (PWDA), which is a chassis mounted shuttle valve with hydraulic pressure from one circuit on each side of the shuttle. The idea is that any leaks in a circuit will lead to a pressure loss in that side under braking, allowing the shuttle to slide over towards that circuit and trigger a dash warning light. They're expensive and failure prone, and cause trouble when bleeding the system. A better and simple alternative is to use the reservoir cap from a Discover, RRC or Defender that has a float sensor, and wire that up to the dash warning light. That way, even a very slow leak that is too small to trigger even a perfect PWDA valve will still show up before you lose the brakes, and you won;t have so much cost or trouble with bleeding.

[Scooby Jim]

You will need the 2.6/V8 master cylinder that goes with those slave units. A single circuit master would be dire. You will need servo assistance, so if you previously had single circuit brakes, you also need the pedal box assembly, servo and vacuum system from a donor vehicle (any 109 or servo assisted 88, not specific to 2.6/V8).

Yep I bought everything off the same vehicle, removed them myself.

The Master and servo is single line anyways, and is also being stripped down and rebuilt.

Pic from when I trial fitted it.

[Snagger]

Wow - I'm surprised at a V8 having single circuit brakes.

[greenmeanie]

Any dual circuit 109 mc will do. The stock 109 cylinder is a common with an adapter is a common replacement in 101s using the same 6 cyl big brakes.