Upgrading late 110 brakes

[ashtrans]

Hi All,

I have a customer with some very heavy late 110's, mainly TD5's and Puma's,

Hi is keen to try and improve the brakes and I am looking for some info on this, I am not sure but I guess they are getting hot and fading.

so far I have seen you can get aftermarket drilled/grooved discs and different pads but are there any other options worth considering.

thanks for any help,

Dave

[Soren Frimodt]

Hej Dave. A really good upgrade regarding hot brakes is the brake pads with Sintered metal. I'm not 100% sure what you call these in English, but you know them, it's those where you can see small bronze-threads mixed into the padding itself. I haven't tried this on a 110 in specific, but I'm a Motorcycle mechanic and on these it makes a-hell-of-a difference! So that and drilled/grooved discs and I would think that is as good as it gets. Or if you could find some larger diameter discs, but I don't know if that is possible.

[Aragorn]

if it is fade, you want to try changing the pads for some that are designed to work at much higher temperatures, and also change the brake fluid to something like Castrol SRF, as again it will operate much hotter before boiling.

EBC do a few pad upgrades for the defender that might be worth trying, but personally i'd be throwing some Mintex M1144's in there, they will make a BIG difference.

[Soren Frimodt]

Exactly Aragorn. 'Cause the thing about hot brakes is that the pads creates a gas when at a certain temperature and this gas makes them "float" on the disc, hence less braking power. And when you fit these Sintered metal pads, the heat will be transferred at a much faster rate because of the bronze and directly into the piston, which will then guide it to the caliper etc etc. But also the brake fluid will rise in temperature as the piston gets warmer. So you want to use some DOT5 or more and change it regularly.

[zoltan]

Don't bother with cross drilled discs, it is a matter of when rather than if they will crack from heat around the drillings. Grooved discs have nearly the same advantage of degassing pads and maintaining a good pad/disc surface but the risk of cracking is greatly reduced.

I would also avoid E** pads in preference for Mintex or Ferodo. E** pads have too much variation in friction level between batches and even pads in a box. If we get customers at work with issues with the car pulling to one side or vibration under braking, more often than not it is these budget pads at fault. It is something to do with the way they are pressed.

As Aragorn says, Mintex M1144 is a good compound as would be Ferodo DS2500. Both have good cold friction and will work well at disc temperatures up to 600 degrees C

Castrol SRF is a hugely expensive option for a high temperature brake fluid. To really get the best out of it it needs to be changed at an unacceptably short period of usage as it is very hygroscopic. At £38 per 500ml there are cheaper options available like Motul 600 or Millers race fluid with similar performance. Race fluids only retain their advantages when changed regularly.

I presume these are working under standard rims so bigger diameter and wider discs are not an option?

[petethepilot]

Grooved & drilled discs, EBC, Ferodo or other Racing quality brake pads, good quality racing brake fluid (Castrol SRF is the best) and braided stainless steel brake hoses. Then complete overhaul for the brakes: new seals, check and clean the pistons and replace if necessary.

Then you will have sufficient brakes!

It´s typical for the Defender, that the rear brake pistons get stuck, thus deteriorating the braking power of the car, and also makes the brakes feel hard, that´s why the overhaul is vital especially in the rear.

The result are soft, very agile brakes with a lot of stopping power, very consistent because brake fading is virtually non-existent.

That should be enough, after that it really starts to become expensive; larger discs, 8-pot calipers, larger wheels etc...

[GL88]

Dave,

I don't have much to add to what others have said save to say I'm running EBC Green Stuff in my TD5 90 and as I'm in Harpenden you'd be welcome to have a drive. When I changed to these pads I felt they gave less initial bite but quickly build up the stopping power to the point that they easily overwhelm the grip of the (standard AT) tyres on dry roads and I'm glad to have ABS. Having said that so did the standard pads. However I don't tow or heavily load the vehicle and I've never experienced fading (before or since the pad change).

I'm around next Friday afternoon and I was going to send you an email with contact details but I don't seem to be able to get on your website at the moment so I've sent you a private message instead.

Guy.

(edit for grammar)

[Les Henson]

I've fitted green pads to customers vehicles - there's always been a marked improvement in braking efficiency. I have heard that they wear out quickly though.

Les.

[Daan]

I would suggest larger calipers from an early 110. They have larger pistons and much larger pads and it is a bolt on mod. check for the brake balance once fitted. Stainless pistons will make things slightly better because of less heat transfer to the fluid. of course vented disks as well, if they are not fitted already. Then pads as already mentioned.

Daan

[Adam001]

Just a comment on a earlier post about Dot 5. the temperature advantage is very vague. It is a classification of the regulations to meet DOT5. I.e. the fluid must not be below a certain boiling point, which with DOT5 is higher than DOT4, however this does not mean the DOT4 fluid is lower than the DOT5.

Also a popular fact is that DOT5 is impervious to water, this is not true, while it does not mix, the water present finds the lowest point...the caliper, which then boils very quickly at just over 100C, whereas DOT4 mixes with water and still retains a higher boiling point.

Also you need to take into account campatibility issues with using a silicone based fluid.

Another vote for Mintex 1144s though Good value with good performance and used in the rally scene

[Aragorn]

DOT5.1 is a very different case to DOT5 though.

5.1 is polyethylene glycol based fluid, just like DOT 3 and DOT4.

5 is silicone based.

5.1 is better than 5 in terms of boiling points, and doesnt have the disadvantages that Adam001 mentions. http://en.wikipedia.org/wiki/DOT_5.1

Also, Daan mentions larger calipers.... ALL 110 front calipers have 46mm pistons afaik. Early 90's have smaller ones, but they changed around the time of the 300TDI to make them the same as the 110.

[Adam001]

I stand corrected! Must read up on that!

[zoltan]

Silicon fluid was developed for the US military who wanted to park vehicles up in store for many years without the fluid deteriorating supposedly

It is completely useless stuff which froths badly, compresses much more than glycol based fluid and doesn't mix with glycol based fluid. As Adam says the water miscibility issue is also a problem for performance use.

[Mo Murphy]

DOT 5 will also rot any rubber in the system unless it was designed to work with DOT 5.

Mo

[ashtrans]

thanks very much for the ideas here,

I will first suggest fitting groved discs, better pads and the Mintex 1144s,

Dave

[Bush65]

Pads, fluids & discs have been covered above, and all of these relate to brake fade, which Dave thought was the issue.

However if brake pedal pressure/feel is also an issue, it can be improved by replacing stock flexible lines with teflon lined, stainless steel.

[robhybrid]

just a thought, can you check very carefully around servo where the master cylinder bolts on, get someone to press the brakes HARD with the engine running. I have seen master cylinders crack and the crack is not visible unless the brakes are pressed hard.

With this fault the servo appears to be working fine when the brakes are pressed lightly so you don't notice the lack of servo when you are driving other than poor quality brakes.

A mate of mine changed his 90 brakes to 110 vented to try and improve his brakes when this was the fault.