460 brake circuit

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Nick123
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Big "Shout-Out" to Loch Shiel Motors of Acharacle who came out and loaded our 1988 460 onto their truck when a rear brake pipe failed as we were coming down steep Liddesdale Hill today.

Fortunately the handbrake did a splendid job of stopping us and the 1.5 tonne trailer behind when the brake pedal went to the floor.

I thought that this vehicle had a split brake circuit.  i.e. two triangular circuits meaning that if one failed the other would continue to work, albeit on three wheels only.

Apparently not though.

Hmmmm...

Nick123
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Re: 460 brake circuit

Can anyone elucidate, please?

Pistonhead
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Re: 460 brake circuit

I am working on theory I might have, just need to verify it if I still have my G-Files records on a twice crashed computer.

Nick123
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Re: 460 brake circuit
Bump! Can anyone out there clarify this, please? We live in a hilly area... Many thanks, Nick.
bigblock
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Re: 460 brake circuit

Hi Nick

I think there are two types of split system on the 460.  The earlier type is just a simple front/rear split, one connection from the master cylinder for the rear brakes and one connection for the front brakes. The later type has one connection from the master cylinder for both front and rear brakes and a second connection that only works the front brakes. This type can be identified by having two brake pipes connected to the front caliper.

Although neither of these is a diagonal type split system across both axles you should still have had braking on the front axle if the rear brake pipe burst. Definetly worth investigating why this did not happen, have there been any modifications to the braking system over the years ?

Nick123
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Re: 460 brake circuit
A fulsome answer, BigBlock. Thank you. I will rummage and investigate tomorrow. We (including trailer) did stop as we came down Liddesdale but it was something of a buttock clenching moment and I felt better getting Loch Shiel Motors to come to our rescue - and take the trailer + LandRover too! It was being delivered to them anyway. Are you anywhere near Fort William? We're along the B849 Drimnin road beyond Lochaline. Thanks again. That's appreciated. All the best, Nick.
Jdring
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Re: 460 brake circuit
Blimey that's scary. Shouldn't happen for sure.
bigblock
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Re: 460 brake circuit

Nick123 wrote:
A fulsome answer, BigBlock. Thank you. I will rummage and investigate tomorrow. We (including trailer) did stop as we came down Liddesdale but it was something of a buttock clenching moment and I felt better getting Loch Shiel Motors to come to our rescue - and take the trailer + LandRover too! It was being delivered to them anyway. Are you anywhere near Fort William? We're along the B849 Drimnin road beyond Lochaline. Thanks again. That's appreciated. All the best, Nick.

Hi Nick, I am in the Cairngorm National Park not far from Grantown-on-Spey. I used to get the Lochaline-Fishnish ferry over to Mull during my rally days but I have never driven further north towards Drimnin. Can you still get a ferry from Drimnin to Kilchoan on Ardnamurchan. I nearly made that trip a while back to look at a house but then my wife found its location on a map and that was the end of that, a little bit to remote for her !   Have you got a boat Nick you live in a fantastic coastal location, I used to keep one down at Kilmelford.

Doug.

 

Nick123
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Re: 460 brake circuit
Thanks for coming back, Doug. Although I don't have a boat myself I used to work on the L/A - Fishnish run and very likely sold you tickets. October Rally Week was always a buzzing time with people really enjoying the adventure. Great fun! During the season there is a 12 passenger foot ferry from Drimnin - Tobermory. Hope to see you one fine day. All the best, and thanks again, Nick.
Nick123
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Re: 460 brake circuit
P.S. I also worked on the Tobermory - Kilchoan ferry: the Dolphin Run. Another great crossing. No two days, no two hours were ever the same. Kilchoan's not that remote. Tobermory and its Co-Op is only a ferry hop away while the bright lights of Fort William are barely a couple of hours by road!!!
bigblock
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Re: 460 brake circuit

So you had a very big boat smiley.  Keep us posted on how you get on with your brake repairs, it will be interesting to learn what caused the spit system to fail.  It's a good thing your handbrake was in good condition and allowed you to slow the vehicle. Were you able to shift the transfer box into low ratio to help you slow down ?

Jdring
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Re: 460 brake circuit

I bet he was too occupied with both hands on the hand brake to try transfer shifting.  Sticking it in 2nd gear is probably the best hoped for?

Nick123
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Re: 460 brake circuit
Loch Shiel Motors of Acharacle replaced the corroded and split rear brake pipe. With hindsight I think the following happened: Going down steep Liddesdale hill with a LandRover 90 on a trailer behind I tried to stop and pull into a passing place to allow a lorry further down a clear run up the hill. My right foot stamped the brake pedal. We began to stop. I stamped the brake pedal again by which time much of the brake fluid had been forced out of the system. With my left hand I grabbed the handbrake and we (G-Wagen, trailer, LandRover) stopped pleasingly quickly. There was no time to juggle hi-lo ratios. Once stopped I pressed the brake pedal again. The brake fluid had all but gone and there was very little resistance. Phew! It was time to call the AA... aka Loch Shiel Motors.