L19MUD Posted August 29, 2023 Share Posted August 29, 2023 2 hours ago, FridgeFreezer said: I'm a little on Carrol Smith's side on the whole warped disc thing... https://www.brakes-shop.com/brakepedia/general/myths-of-the-braking-system In that stuff that gets blamed on warped discs almost never actually is a warped disc. Interesting read. What that does agree with though is that keeping the heat out of things as much as possible is a good thing Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted August 29, 2023 Share Posted August 29, 2023 1 hour ago, L19MUD said: What that does agree with though is that keeping the heat out of things as much as possible is a good thing That's what temperature labels are for Quote Link to comment Share on other sites More sharing options...
ped Posted August 29, 2023 Share Posted August 29, 2023 i run vented on the front and solids on the rear in my 110s but i do carry a fair bit of weight and tow well loaded tralers and we have big hills in gods country Quote Link to comment Share on other sites More sharing options...
Ed Poore Posted August 30, 2023 Share Posted August 30, 2023 To be fair I think the single biggest reason discs are preferable is the lower maintenance overhead as they are self adjusting. Particularly important if you're the one doing the maintenance. One point not brought up is that drums are effectively self applying, once applied they effectively lock themselves on with minimal effort. However that can also mean that you get slightly less feedback from the brakes. Whether that difference is noticeable is dependent on a lot of factors. When I adjusted the Sandringham's drum brakes properly it stopped a damn sight faster and with lower effort (from me) than I ever could in the disc braked Defender. As if to prove a point though it failed the initial MOT on braking effort because I'd forgotten to adjust them it has been so long since I'd had a drum braked vehicle. Adjusted the tester came back from the test drive rubbing his head with a big red spot on it where he'd whacked his head against the windscreen. 1 Quote Link to comment Share on other sites More sharing options...
tuko Posted August 30, 2023 Author Share Posted August 30, 2023 20 hours ago, FridgeFreezer said: Worth noting that vented/grooved/drilled discs don't stop you any better than solid discs - they just let you do more hard braking before they overheat. Unless you're boiling your brake fluid on a regular basis there's no benefit at all in buying flashy discs, especially on the rears. Given how hard it is to boil the brakes even on a heavily laden vehicle with the stock discs + drums setup I'd suggest most folks don't need that level of "performance". I did manage to overheat the (very old) brake fluid on the ambulance snaking down Col d'Petit St Bernard but that's a 3 ton truck and it's a very steep & twisty road even by alpine standards, it's never happened before or since even towing 3 tonnes or driving other notorious alpine roads around Europe. Adding to the first paragraph, if I'm able to upgrade my brakes including changing to discs on the rear, I should be able to travel the same roads and have a braking system that in therory should be more effective by lowering the risk of overheating. The given is that I don't change my driving habits of course. Our last trip in Norway I managed to polish the front discs to the point where they felt like they needed more pedal pressure to get the same result and nearing the end of the trip the left rear brake cylinder developed a drip/leak. I do believe now that the rear brake cylinders are original and need replacing. This therefore gives me the opportunity to get the braking system that I always wanted on the rear, which are discs. A point which has been brought up and has caught my attention is an electric vacuum pump and doing away with mechanical pump all together. Is it a matter of simply adding an electric vacuum pump to the existing vacuum line or are you required to add a pressure switch ( and then what pressure range? ) and a relay? Quote Link to comment Share on other sites More sharing options...
tuko Posted August 30, 2023 Author Share Posted August 30, 2023 19 hours ago, FridgeFreezer said: I'm a little on Carrol Smith's side on the whole warped disc thing... https://www.brakes-shop.com/brakepedia/general/myths-of-the-braking-system In that stuff that gets blamed on warped discs almost never actually is a warped disc. That was a good read, thanks. 1 Quote Link to comment Share on other sites More sharing options...
Jon W Posted August 30, 2023 Share Posted August 30, 2023 Ahhh but that is 6 drums vs 4 discs. But yes drums require less effort hence many didnt have a servo originally Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted August 30, 2023 Share Posted August 30, 2023 1 hour ago, tuko said: A point which has been brought up and has caught my attention is an electric vacuum pump and doing away with mechanical pump all together. Is it a matter of simply adding an electric vacuum pump to the existing vacuum line or are you required to add a pressure switch ( and then what pressure range? ) and a relay? That sounds more complicated than the mechanical solution? And yes you'd need a switch to cut the pump off and likely a little reservoir so it's not losing vacuum & cycling every time you hit the brakes. Some cars have little electric vac pumps for central locking or cruise control etc. but most just have them on the alternator these days as far as I can tell. 1 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted August 30, 2023 Share Posted August 30, 2023 A lot of people just use the brake light switch to run the pump, and find it more than adequate, I think @simonr used one like this on hid electric Freelander? 1 Quote Link to comment Share on other sites More sharing options...
simonr Posted August 30, 2023 Share Posted August 30, 2023 48 minutes ago, Bowie69 said: A lot of people just use the brake light switch to run the pump, and find it more than adequate, I think @simonr used one like this on hid electric Freelander? Initially, that's how I did it just because it's simple. However, it needs a bigger / more powerful pump than using a vacuum pressure switch and a vacuum reservoir. My original solution was to use a 750W motor from an electric scooter driving a vacuum pump, IIRC from a diesel Series LR which was belt driven? Eventually the pump gave up and I replaced it with an electric brake pump from a modern vehicle, with the switch & reservoir. This worked much better as even with a high power pump, you can feel the delay when you press the pedal. 1 2 Quote Link to comment Share on other sites More sharing options...
Snagger Posted August 30, 2023 Share Posted August 30, 2023 On 8/29/2023 at 2:30 PM, FridgeFreezer said: Worth noting that vented/grooved/drilled discs don't stop you any better than solid discs - they just let you do more hard braking before they overheat. Unless you're boiling your brake fluid on a regular basis there's no benefit at all in buying flashy discs, especially on the rears. Given how hard it is to boil the brakes even on a heavily laden vehicle with the stock discs + drums setup I'd suggest most folks don't need that level of "performance". I did manage to overheat the (very old) brake fluid on the ambulance snaking down Col d'Petit St Bernard but that's a 3 ton truck and it's a very steep & twisty road even by alpine standards, it's never happened before or since even towing 3 tonnes or driving other notorious alpine roads around Europe. Yes. I had dimpled and grooved EBC discs but I’m replacing them (because they are rusted) with standard AP or Lockheed discs as they are perfectly adequate. I read a few negative comments on here about them, but I found the EBC “Green Stuff” pads very good, though I have asked the restorers to fit standard Mintex pads this time because I think the standard spec is plenty for my needs. If you want improved braking for towing, though, I’d still recommended those EBC products. 1 Quote Link to comment Share on other sites More sharing options...
Snagger Posted August 30, 2023 Share Posted August 30, 2023 4 hours ago, simonr said: Initially, that's how I did it just because it's simple. However, it needs a bigger / more powerful pump than using a vacuum pressure switch and a vacuum reservoir. My original solution was to use a 750W motor from an electric scooter driving a vacuum pump, IIRC from a diesel Series LR which was belt driven? Eventually the pump gave up and I replaced it with an electric brake pump from a modern vehicle, with the switch & reservoir. This worked much better as even with a high power pump, you can feel the delay when you press the pedal. That sounds similar to what Mike did on one of his Britrest videos when he tried the same thing. He found that a vacuum bottle was needed and was fiddling around with a timer relay to run the pump after applications instead of a pressure switch, but I can’t remember the rationale. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted August 30, 2023 Share Posted August 30, 2023 I was using a small BMW air suspension reservoir as a vacuum reservoir for my difflocks before I moved to compressed air, they're on eBay for £10-£15. Quote Link to comment Share on other sites More sharing options...
tuko Posted September 25, 2023 Author Share Posted September 25, 2023 This past weekend I've made some progress on my mission for better brakes on the Defender. The drum salisbury axle is now in the garage and the replacement disc salisbury is installed. Changing to discs there is a more positive braking feeling from yesterdays test drive. The next stage will be changing the brake booster from the type 80 version to a dual diaphragm from a Disco 1. But before doing that, the booster fork will need to be lengthened so that it fits the Defender brake pedal. More to follow. Todd. 1 Quote Link to comment Share on other sites More sharing options...
Tobias Posted October 3, 2023 Share Posted October 3, 2023 I like your ideas on brakes, disco 1 booster and electric vac pump.. i was tutored on Tesla/Bosch ebrake electric brake booster at the Botkyrka MK offroad meet in August. I found a used one in Norway and I’ll try it on the Pulse replica.. maybe we can meet up somewhen and compare brakes? Tobias 1 Quote Link to comment Share on other sites More sharing options...
Daan Posted October 3, 2023 Share Posted October 3, 2023 Also worth checking the piston diameter in your front calipers; There is 41 and 46mm versions, bigger is better obviously. The bigger caliper has bigger Pads as well. 0n a 110, wheelbase You might get away with no proportioning valve at the back if you run the bigger calipers. On my 88, it did need a proportioning valve. 1 Quote Link to comment Share on other sites More sharing options...
tuko Posted October 4, 2023 Author Share Posted October 4, 2023 23 hours ago, Tobias said: I like your ideas on brakes, disco 1 booster and electric vac pump.. i was tutored on Tesla/Bosch ebrake electric brake booster at the Botkyrka MK offroad meet in August. I found a used one in Norway and I’ll try it on the Pulse replica.. maybe we can meet up somewhen and compare brakes? Tobias Hej Tobias, I'm away this weekend with SLRK but finger crossed I can replace the brake booster within the next 2 weeks then after that I'll consider weather or not if I use an electric vacuum pump from a V70. Jupp, it's been too long since we've crossed paths. Todd. Quote Link to comment Share on other sites More sharing options...
tuko Posted October 4, 2023 Author Share Posted October 4, 2023 15 hours ago, Daan said: Also worth checking the piston diameter in your front calipers; There is 41 and 46mm versions, bigger is better obviously. The bigger caliper has bigger Pads as well. 0n a 110, wheelbase You might get away with no proportioning valve at the back if you run the bigger calipers. On my 88, it did need a proportioning valve. Daan, Off the top of my head I don't remember the piston size on the front, may have to pull a tire after work and see. Thanks. On my 88 I have 46mm front and rear plus the disco 1 booster. With all the camping gear installed it stops literally on a pence and that vehicle does have the proportioning valve. Todd. Quote Link to comment Share on other sites More sharing options...
Jon W Posted October 4, 2023 Share Posted October 4, 2023 I can't remember what I used in my rebuild on my 90 it was drum brake many moons ago then swapped to a few different rear axles over last few decades. It used to lock up on the rear before the front which was a bit hairy on corners. During rebuild either the balanced value got shaken around and freed up, or it is the defender td5 master cylinder and servo that i put on it that has sorted out the brake balance and also made the brakes so much easier to press. Very happy with the brakes now. Defender 110/130 vented fronts and discovery rear brakes 1 Quote Link to comment Share on other sites More sharing options...
simonr Posted October 5, 2023 Share Posted October 5, 2023 In the dim & distant past, I had a 1986 110 with disc front & rear drum brakes on a Salisbury Axle - and they never provided sufficient braking, even having replaced most of the usual suspects. I replaced the brake internals with a Series 3 Twin Leading Front setup. It made a significant difference. It's a good, cheap option. Eventually I found a Disc braked Sallisbury & fitted that - then the brakes were really good! 2 Quote Link to comment Share on other sites More sharing options...
tuko Posted October 6, 2023 Author Share Posted October 6, 2023 On 10/4/2023 at 10:54 AM, Jon W said: I can't remember what I used in my rebuild on my 90 it was drum brake many moons ago then swapped to a few different rear axles over last few decades. It used to lock up on the rear before the front which was a bit hairy on corners. During rebuild either the balanced value got shaken around and freed up, or it is the defender td5 master cylinder and servo that i put on it that has sorted out the brake balance and also made the brakes so much easier to press. Very happy with the brakes now. Defender 110/130 vented fronts and discovery rear brakes Jon, I've been reading all the comments and have been checking prices on converting to vent disc's on the front. I'm not under the illusion that it's going to reduce my braking, weather prolonging or delaying overheating is the benefit I'd like to have in the mountains. So far with the change to the disc salisbury axle I've noticed a more straight line and even (front to back) braking but still it does take some effort on the pedal. Yesterday after work I lengthened the fork on the Disco 1 brake booster by 10mm, when the weather allows I will change that. I'm hoping that it will give the same improvement as it did on the 88". Todd. Quote Link to comment Share on other sites More sharing options...
Little mule Posted October 9, 2023 Share Posted October 9, 2023 Hi all i thought I might throw my hat in the ring and give you a personal experience with the bigger Callipers and disco brakes . i changed out my front Callipers to the BIG 110 ones and solid discs . I used all EBC pads ,rotors, I used the factory disco ABS system and the factory disco master cylinder three port system . when I took the truck for a drive I almost killed myself trying to stop lol. the master I used was the three pipe disco system . I pushed on the brake peddle and it went right to the floor and bottomed out the master cylinder . I had no brakes unless you pumped the peddle once then it came up hard from the very top and had little travel . it also would hardly stop the truck . I changed out the brake peddle assembly and installed a RRC brake booster with the very large 110 brake master cylinder . I had to T off the rear brakes because the master only had two ports . I disconnected the ABS because this was my off road truck . let me tell you once I installed the correct master and the big booster from the RRC WOW did the truck stop well . I had a lot more control modulating the brake peddle and you could actually feel the brakes working and when they got hot I had to ease off the brake peddle so I did not lock them up . the RRC peddle assembly brake booster also has the proper bolt pattern straight across like a 110 brake master cylinder also the master cylinder has the proper volume for the bigger front Callipers . The 110 master bolts onto the booster with a little modding to the mounting bolt holes I think . The rod from the peddle to the brake master had to be adjusted as well . I don’t remember if it was shortened or lengthened it’s been a while lol . Worst case you can use a GM half ton brake master and will have all the peddle column you need. the brakes just worked very well . Off reading I could now stop and hold on the hills instead of having to put my truck into neutral so the brakes would hold in low range . the disco brakes in low range off reading would not hold at all, the truck at idle would just drive right through any amount of pressure I applied . Apparently this is a disco thing . my next set up on my RRC build will be hydro boost with the big 110 front Callipers and proper 110 rear Callipers (slightly bigger pistons than a disco) this set up stops the truck is a hurry if needed and holds back the truck on hills with out putting the tranny in neutral . speaking of big Callipers does anyone know where I can get the spacer and rubber used between the Calliper half’s and spacer plate when used on vented discs . I know you can get the proper rubber seals with the regular solid Callipers but I have not been able to find any of the longer spacers and rubber seals that go between the calliper and the spacer so the calliper is wider and fits vented rotors . Just my thoughts Tony Quote Link to comment Share on other sites More sharing options...
Snagger Posted October 9, 2023 Share Posted October 9, 2023 1 hour ago, Little mule said: disco brakes in low range off reading would not hold at all, the truck at idle would just drive right through any amount of pressure I applied . Apparently this is a disco thing . No, just a fault somewhere. My 109 has a full Discovery brake system and it stops on a sixpence, every bit as sharp as the power brakes on my late RRC and better than the ABS system on the 2009 90XS. It might be a common issue on Discoverys, but that is not the same as normal. Quote Link to comment Share on other sites More sharing options...
Little mule Posted October 9, 2023 Share Posted October 9, 2023 Thanks for the reply snagger . the brakes on my two door RRC are really good for just factory brakes . the issue with my disco was the master cylinder volume out put was too small for the big 110 brake Callipers and bottomed out on the first push of the peddle but then worked if the peddle was pumped once or twice. Kind of like driving a old series truck lol. if I can’t get the hydro boost system to work for me I’ll install a second vacuum tank and use a electric vacuum pump from a BMW . the 200/300 Tdi I’m in the process of building will have a vacuum pump off the 200 and the cylinder head off a 300 with a skyline/ rover turbo setup . I’ll need all the braking power I can get once the boost is turned up . I should be able to maintainer about 25 lbs of boost under normal driving . Quote Link to comment Share on other sites More sharing options...
Snagger Posted October 11, 2023 Share Posted October 11, 2023 I don’t know about how the single loop brakes on earlier Series behaved, but again, the twin-line system on SIII 109s and late 88s was firm and very effective if maintained well. Before the coiler axles were fitted, my 109 on its original spec brake system could easily lock all four wheels on dry tarmac with 235/85 tyres, as could my wife’s Lightweight on its standard brakes and tyres. Land Rover steering and brakes are much maligned, but when well maintained they are more than adequate on a standard(ish) vehicle. If you have a 200Tdi, I would recommend using the original head rather than a 300 if increasing the boost - 200 heads are reputed to be a fair bit more resilient. Quote Link to comment Share on other sites More sharing options...
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