Brake upgrade options for re-plated Hymer B668

[mike.lamb]

Hi all, despite an extremely conscious attempt to engine brake as much as possible, driving our fully loaded (4 of us plus 4 bikes) motorhome through the mountains of France last year led to some very smoky brakes and everything getting extremely hot.

This was really only on the long trips with lots of ups and downs, but still something I’d like to resolve.

I know we started our trip under the 4500kg MTPLM with a full tank of water, so i’m quite sure we were still under while driving through the mountains with little water.

Before our next big trip, I’m changing the Thule bike rack to something more robust and chassis mounted, fitted at LNB Towbars in Bristol. Our kids are still small, hence small bikes but I feel like the Thule hanging off the back wall is pushing it as it is, so getting this done ahead of the next size of bikes.

We’ve also had VB air suspension fitted at SAP, and we’re up plating via SvTech to ensure the back axle can comfortably take the new bike rack within limits.

I’d already changed the alloys and tyres when we bought the van, and made sure those were within limits for the re-plate.

I’m interested in what options there might be to upgrade the brakes. I see the van sat on the drive next to my X5 with it’s massive ventilated discs. The discs on the van seem tiny in comparison.

Has anyone looked at upgrading their brakes or familiar with the options available?

Thanks!
Mike

 

[ambulancekidd]

Stick to very high quality brake pads, the difference is like night & day, they'll cost more, but what price for safety?
Brembo & Mintex spring to mind & are your new alloys allowing enough cool air into the brakes?

 

[SandraL]

We are fiat on heavy chassis plated at 4750, running about 4350kg.
On steep decents we use 2nd gear at 3000 rpm, its slow and we pull over whenever possible to let the inevitable queues past.
I dont know of a brake upgrade.

 

[mike.lamb]

Stick to very high quality brake pads, the difference is like night & day, they'll cost more, but what price for safety?
Brembo & Mintex spring to mind & are your new alloys allowing enough cool air into the brakes?

Thanks - any meaningful difference in discs too? The face of the wheels are quite open but there isn't a huge gap between the caliper and the alloy

 

[cmcardle75]

Generally, it is about driving style. Even in the mountains, you shouldn't be using your brakes, except on the most serious declines. You should be prepared to go right up to the red line before braking. Expecting to keep it under 3000 rpm will soon cook your brakes. You shouldn't sit on your brakes until you are in 1st gear at the red line. By this time, you are unlikely to be exceeding 20mph, which should keep the remaining braking effort within the ability of the braking system to dissipate heat.

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[mike.lamb]

sounds like I need to be braver letting the revs increase. I was doing a lot of engine braking, very conscious whenever hitting the brakes and intentionally not building up speed but the engine noise at higher revs was definitely having me lean on the brakes assuming that was the lesser evil

 

[Landy Andy]

Make sure your brake callipers and their slides are in good order, otherwise they may be dragging slightly and thus starting off hot, before they are being used.

 

[cmcardle75]

sounds like I need to be braver letting the revs increase. I was doing a lot of engine braking, very conscious whenever hitting the brakes and intentionally not building up speed but the engine noise at higher revs was definitely having me lean on the brakes assuming that was the lesser evil

Brakes are for slowing you down, not for stopping you speeding up. If you need to press them to stop you speeding up, you're going too fast, or in too high a gear, or both. You should immediately change down, or if that would result in red-lining, slow down first so you can change down. If that's not enough. Drop another gear. Until you are in 1st.

It is scary for the first few times in a heavy diesel vehicle to run it up to the red line, particularly as they have poor noise deadening compared to cars. However, I spent two weeks of the summer driving kids up and down Porlock Hill in 4.3 tonne minibuses. You soon get used to the noise! But the smells and fire pouring off the cars of poorly trained Londoners you get at the bottom of Countisbury Hill are even more terrifying than the engine noise. At least Porlock Hill has lots of bends and escape lanes. Countisbury might be technically a lower maximum gradient, but it is straight down. You'd be doing 80mph when you hit the bottom if the brakes failed in high gear.

The emergency services are quite used to it though. I did have to do a quick trip as a passenger from Porlock Weir to County Gate to pick up a bus, parked at the start of a hike. On the way up, Porlock Hill was blocked by a car that had failed to make the final turn, presumably having descended in 5th until the brakes died and ended up in the cottage garden wall. We had to take the toll road (always free when Porlock Hill is blocked by an incompetent driver). By the time I'd returned back down for the pick-up 20 minutes later, there was no trace of the accident. The cottage wall at the bottom of the hill is basically built like the anti-terrorist defences at Parliament with massive steel foundations. Even a large truck can splat against it and there is not even a scratch on the stone. It probably happens weekly.

 

[Googlebot]

You could upgrade to racing pads or similar if you can find some to fit, they are designed to work at higher temperatures so won’t fade as much.

Then there are drilled discs to help cooling.

Has to be said though, it’s a van so you might be out of luck.

 

[cmcardle75]

Brakes are for slowing you down, not for stopping you speeding up. If you need to press them to stop you speeding up, you're going too fast, or in too high a gear, or both. You should immediately change down, or if that would result in red-lining, slow down first so you can change down. If that's not enough. Drop another gear. Until you are in 1st.

It is scary for the first few times in a heavy diesel vehicle to run it up to the red line, particularly as they have poor noise deadening compared to cars. However, I spent two weeks of the summer driving kids up and down Porlock Hill in 4.3 tonne minibuses. You soon get used to the noise! But the smells and fire pouring off the cars of poorly trained Londoners you get at the bottom of Countisbury Hill are even more terrifying than the engine noise. At least Porlock Hill has lots of bends and escape lanes. Countisbury might be technically a lower maximum gradient, but it is straight down. You'd be doing 80mph when you hit the bottom if the brakes failed in high gear.

The emergency services are quite used to it though. I did have to do a quick trip as a passenger from Porlock Weir to County Gate to pick up a bus, parked at the start of a hike. On the way up, Porlock Hill was blocked by a car that had failed to make the final turn, presumably having descended in 5th until the brakes died and ended up in the cottage garden wall. We had to take the toll road (always free when Porlock Hill is blocked by an incompetent driver). By the time I'd returned back down for the pick-up 20 minutes later, there was no trace of the accident. The cottage wall at the bottom of the hill is basically built like the anti-terrorist defences at Parliament with massive steel foundations. Even a large truck can splat against it and there is not even a scratch on the stone. It probably happens weekly.

BTW, it is even scarier going up. I went up towing a 3 tonne trailer. I reckon total weight about 7 tonnes with 150bhp. Flat out in 1st on the steepest bend it crept down to 9 mph. And it is so tempting to let off approaching the bend, which would be fatal. If you stopped whilst towing a trailer, there would be no way of starting again, you'd have to reverse to the bottom. About a mile with little visibility and lots of traffic. I wouldn't have even tried it if there had been kids on board.

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[cmcardle75]

sounds like I need to be braver letting the revs increase. I was doing a lot of engine braking, very conscious whenever hitting the brakes and intentionally not building up speed but the engine noise at higher revs was definitely having me lean on the brakes assuming that was the lesser evil

The red line is the speed the engine manufacturer says you shouldn't exceed. They will have added some leeway before the valves start bouncing off the camshaft. You can quite safely go right up to it without causing any engine damage, although sitting there all the time will definitely accelerate wear. Sitting on the brakes for any period, however, will definitely cause damage to the brakes and might result in death and total destruction if done in the wrong places resulting in fade right before a sharp bend. A minute or two of red-line (with no fuel being injected to warm things up) is definitely the lesser of two evils.

 

[Silver-Fox]

Then there are drilled discs to help cooling.

Something I’m not keen on.

Personally I like grooved

 

[Jamesh]

BTW, it is even scarier going up. I went up towing a 3 tonne trailer. I reckon total weight about 7 tonnes with 150bhp. Flat out in 1st on the steepest bend it crept down to 9 mph. And it is so tempting to let off approaching the bend, which would be fatal. If you stopped whilst towing a trailer, there would be no way of starting again, you'd have to reverse to the bottom. About a mile with little visibility and lots of traffic. I wouldn't have even tried it if there had been kids on board.

I climbed it a few years ago on my road bike probably the worst hill ivey climbed up in UK!

I've done about 25% of the top 100 climbs. Mostly the harder ones!

 

[cyberyacht]

My stepson lives up near the top of Countisbury Hill. Going up Porlock certainly plays havoc with your average fuel consumption. It's meeting a coach coming down that can impinge on your "racing line" on the second corner.

 

[63720]

Has any used the Descent Assist?

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[cmcardle75]

My stepson lives up near the top of Countisbury Hill. Going up Porlock certainly plays havoc with your average fuel consumption. It's meeting a coach coming down that can impinge on your "racing line" on the second corner.

Indeed. I was terrified of meeting the Coaster coming down when towing going up. It would have resulted in a very embarrasing half hour of reversing to have another go. It was fine when running solo. I think it would have restarted. Maybe not on the actual bend, but on the previous straight.

 

[cyberyacht]

Descent Assist? Don't think my 2016 Carthago has that. Gravity seems to manage on its own.

 

[Bartyfixedit]

What wheels have you fitted? If they are steel wheels have you fitted wheel trims?

 

[mike.lamb]

What wheels have you fitted? If they are steel wheels have you fitted wheel trims?

Alloys, the faces of them are quite open.

 

[dazandandrea]

May have been said before but i would look at the discs/ drums , pads/ shoes, master/ slave cylinders, hoses and brake fluid already fitted or being used.
Usually an original system correctly set up and operating correctly should be more than capable of stopping you.

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[BouncyBoatFolk]

Generally performance brake pads give something up, that is usually the performance is less effective when cooler. Additionally, the compound used for the pad will not last as long as a standard compound. When I was MXing I carried different pads for different tracks, and special sintered pads for wet and muddy tracks, and a stainless disc rotor, also braided hoses that expanded less.
Mike.

 

[fat haggis]

Upgrading the brake fluid will also help stopping power when things get hott.

 

[jopparocks]

The red line is the speed the engine manufacturer says you shouldn't exceed. They will have added some leeway before the valves start bouncing off the camshaft. You can quite safely go right up to it without causing any engine damage, although sitting there all the time will definitely accelerate wear. Sitting on the brakes for any period, however, will definitely cause damage to the brakes and might result in death and total destruction if done in the wrong places resulting in fade right before a sharp bend. A minute or two of red-line (with no fuel being injected to warm things up) is definitely the lesser of two evils.

I would like to follow your advice but am in France at moment in old 3 litre mercedes Hymer which has no rev counter. I've been using engine braking and normal braking when going down hills. Brakes not working that great on first press of the pedal then after taking the foot off the brake and then applying again I get much better grip. I end up on and off brake pedal all way down. Does this sound normal?

 

[ivorantony]

Something I’m not keen on.

Personally I like grooved

Agreed, I fitted grooved discs to my Renault master that also has front vented discs with heavier duty brake pads,
plus a complete flush and renew with DOT 5.1 brake fluid before taking her through the Alps,
the heavy duty pads make the pedal effort slightly higher but not massively so,

 

[Figaro]

Does this sound normal?

Sounds normal to me.
I try and stay off the brakes on decent using engine braking, the when speed builds, give the brakes a good jab, shed some speed then off again for as long as possible before starting again.

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[dazandandrea]

Stay off your brakes as much as you can . Dont boil the fluid. Stop completely if you have too to let things cool down .

 

[63720]

Back in the day I was told to descend a steep hill in the same gear used to go up.
In this weather will be t-shirt and shorts.

 

[Jaws]

error

 

[Jaws]

Hi all, despite an extremely conscious attempt to engine brake as much as possible, driving our fully loaded (4 of us plus 4 bikes) motorhome through the mountains of France last year led to some very smoky brakes and everything getting extremely hot.

This was really only on the long trips with lots of ups and downs, but still something I’d like to resolve.

I know we started our trip under the 4500kg MTPLM with a full tank of water, so i’m quite sure we were still under while driving through the mountains with little water.

Before our next big trip, I’m changing the Thule bike rack to something more robust and chassis mounted, fitted at LNB Towbars in Bristol. Our kids are still small, hence small bikes but I feel like the Thule hanging off the back wall is pushing it as it is, so getting this done ahead of the next size of bikes.

We’ve also had VB air suspension fitted at SAP, and we’re up plating via SvTech to ensure the back axle can comfortably take the new bike rack within limits.

I’d already changed the alloys and tyres when we bought the van, and made sure those were within limits for the re-plate.

I’m interested in what options there might be to upgrade the brakes. I see the van sat on the drive next to my X5 with it’s massive ventilated discs. The discs on the van seem tiny in comparison.

Has anyone looked at upgrading their brakes or familiar with the options available?

Thanks!
Mike

I can only recommend what worked for me and a couple of others I did the job on for the same reasons you state
Change the brake fluid to dot5 s mentioned ( it has a higher boiling point and fit EBC HH sintered pads all round
That will minimise brake fade and not cause damage
BUT
no matter what you change / fit the brakes are always gonna get hot and stinky
Take it slow and stop in a layby often

 

[pagey]

Maybe water spray like the racing trucks but a bit over the top

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