Jump to content

Jake brake?


ajh
 Share

Recommended Posts

Never fitted one, there'd be a lot of work in retro-fitting one to an engine it's not designed for. Have worked on them on big cam cummins lumps. Bloody awkward buggers to set the exhaust valve solenoids up. And if they fail, you'll be left with zero compression, as the valves jam open and the engine won't run.

Very effective though. Oh, and they're noisy as hell.

The problem we had was, oil getting into the solenoid wiring and the solenoids failing - in a TD5 injector loom styleee.

Exhaust brakes are much more simple, much quieter but not as efficient. Still work good though.

Mechanical retarders, can't see any use for one on a Landy, a couple of hundred kilos wrapped round the propshaft :)

Link to comment
Share on other sites

I was using it as a generic term for an exhaust brake, so any pointers at suitable options would be helpful. Mostly I'm concerned about driving fully-laden in the mountains, anything that helps keep the brake system temperatures down is a good idea.

Link to comment
Share on other sites

Oh I see. An exhaust brake is the only viable option in my opinion.

Just a butterfly valve in the exhaust pipe, down-stream of the turbo. Shutting the valve chokes the engine, so you get more engine braking.

Isuzu NQR's have a setup which would easily convert to use on a landy, and they're not air operated either.

Jakobs brakes or retarders would be massive overkill on a LR.

Link to comment
Share on other sites

Jake brake not retrofitable to any engines by landrover , exhaust brake, you need really good exhaust gaskets, as they put quite a lot of extra strain on sealing of system upstream from them , effectiveness depending on engine very variable and also the reaction varies considerably depending on gearing ,and on load and surface . eg you dont use ex brake on poor traction surface esp in low gear as you can very quickly go into skid , you can partly overcome this by fitting abs sensing switching , not really doable using KISS for return gained in landrover size vehicles, waste of time ,unless you are doing a lot of heavy towing thru alpine type terrain . JMHO

Link to comment
Share on other sites

I was using it as a generic term for an exhaust brake, so any pointers at suitable options would be helpful. Mostly I'm concerned about driving fully-laden in the mountains, anything that helps keep the brake system temperatures down is a good idea.

As a matter of interest, do you use engine braking as normal behaviour to control vehicle speed on downhill sections?

I ask because in the UK, and it becomes noticeable in what passes for hilly areas like North Derbyshire, UK drivers are NOT in the habit of using engine braking.

For some reason, possibly regular holidays in Wales as part of a family of 5 or 6 in an ordinary car, I have always, without concious effort, used engine braking as a matter of course. As an aside, when I was introduced to Land Rovers and driving 'off-road' in about 2000, I couldn't understand the very strong emphasis during training of leaving the car in low gear and taking your feet off the pedals, as this was a natural extension of what I did normally. It required no special thought or effort.

The point of all this is that if you follow the old fashioned dictum of 'use the same gear going down as you would use going up', you will save an awful lot of wear and tear on the brakes. If you use a petrol engine, and let the revs get over 3000 rpm, you may find oil drawn up the bores. I haven't found this to be a problem with a diesel engine, possibly because the greater compression means that more braking is available.

A way to monitor if you are in the correct gear (one that gives enough braking) is that on downhill sections you will only have to brake for short distances just before corners, just as you would if the road was level. Speed along any straight or gentle curved sections would be controlled only by the engine braking.

Allow a little flexibility in putting that guide into practise.

I have never driven in the Alps, but feel that FULL exploitation of 'normal' engine braking will pay dividends.

This might mean using 3rd gear, which some people will find odd in a 5 speed gearbox.

It also goes against what I understand is current Advanced Driving / Police driver training, but I feel that reacting to the actual driving conditions is better than following some paper dictum.

Don't take that as a knock against Advanced Driving techniques or Police Drivers, it's more a knock against people who are too rigid in their approach to driving, whatever the Diploma on the wall says.

HTH

Link to comment
Share on other sites

The first thing , that costs nothing is to drive as you had to before modern braking systems, eg you go down the hill in the gear that you would use to climb it . Generally a landrover with disc brakes will handle most terrain adequately within their train weights , an X brake on the trans would add to this capabilty , I dont know its specs, but am sure someone on here will assist you with that. From experience, a 109 with drums at its max + a bit thru alps had to be managed carefully :o .

Link to comment
Share on other sites

Engine brakes also have a nasty side effect. They increase the temperature in the cylinders. This can cause problems with overheating the nozzles on the injectors leading to premature failure. Trucks are now looking at other methods using variable vane turbo's etc.... to try and keep the temperatures down.

I would look at making sure the brakes on the trailer are up to scratch and possibly look at fitting a linked braked system.

Regards

Ed

Link to comment
Share on other sites

isuzu troopers had exhaust brakes as standard. i cut mine out as it was seized, like most others you will come across in the 4jb1. it was cable operated but seemed like quite an obstruction in the exhaust even when open. i imagine you'll find engine braking, wind resistance and normal brakes sufficient for slowing your progress.

Link to comment
Share on other sites

As has already been pointed out above, there is a big difference between an engine brake and an exhaust brake. An exhaust brake would be perfectly appropriate for LR diesels for your intended use in further slowing the vehicle in mountain driving. I have a Jacobs exhaust brake on my 5.9L Cummins Turbo Diesel in my 3/4 Dodge pick up and use it as a supplement to the excellent Dodge disco brakes not only when towing. It definitely extends the life of your brake pads, but not enough to cover the cost of the brake! When towing, it provides a huge confidence boost and coming down the Western Rockies on the way to Moab was very important to have.

I am not familiar with the Isuzu system referenced above, but it is simply an exhaust in-line butterfly valve, so presumably someone with more engineering skills than I could build something for a Land Rover system. Just make sure that with the valve open it isn't restricting flows. And enjoy it!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy