Servo brakes - what's needed?

Howdy,

My 88" currently has Single line 10" brakes (no servo), I plan on fitting a 200tdi when I find one so should probably upgrade the stop pedal too

So I've managed to track down a series servo, pedal and brake tower. I'll be buying new lines and a master cylinder (twin line) and am on the look out for a set of 11" front brakes: http://www.landyzone.co.uk/lz/f60/11-tls-lwb-brakes-axle-251523.html

What else do I need? It's a diesel so rather than fit a butterfly valve thing I plan to fit an electric pump (I'm no rivet counter...) - any suggestions as to which one? Will I still need a vacum tank with an electric pump?

Thanks in advance - and pics to come once I've got all the bits

If you can manage to find one you are going to want the brake shuttle valve. This is the block that goes into the lines between the master and the front/rear circuits and cuts off the failing circuit should one of them lose integrity.

Does the 200TDi not have a vacuum pump a la 2.5D? Thought it did.

ajr

200 has a vacuum pump on it, no need for leccy setup

I ain't got a 200tdi yet though - next on the shopping list

Do I really need the shuttle valve? I heard they're more hassle than they're worth... cost a fortune and clog up?

don't bother with the shuttle valve (PDWA - Pressure Differential Warning Actuator) as it's not essential and all it really does is give you a tell tale light in the event you lose pressure in the rear or front brakes if you get a leak (the fluid is NOT linked through it)

10"sls brakes will stop an 88" quite adequately regardless of the engine under the bonnet as long as they're set up properly, my 88" started out with 10" single line brakes and i could get the rear wheels hovering under heavy braking with the tdi under the bonnet

i've since upgraded to dual line servo assisted (because i got the bits really cheap and i wanted to experiment) but with 11"sls front brakes (yes eleven inch) the stopping hasn't got that much more powerful (tyre traction is the limitation), it's just that there's less effort required from my leg due to the servo assistance

my daily driver now is a 109 with 200tdi under the bonnet, ok i've got 11" brakes all round but still single line and no servo, i hammer the brakes on hard and i'm almost scraping the galvy off the front bumper

this motor is obviously heavier than my 88" plus i also leave more junk in it so is carrying more weight, the secret to good brakes is to set them up properly and use them regularly (this of course is just MY opinion, others may disagree) both of these motors have been my daily drivers for the last five years so they have been worked hard

oh and if you do go for an electric pump you won't need the vacuum tank so sell that/pass it on to a mate who wants it, use a relay to switch the vacuum pump on and trigger that from the brake light switch=instant vacuum

NiteMare said:

don't bother with the shuttle valve (PDWA - Pressure Differential Warning Actuator) as it's not essential and all it really does is give you a tell tale light in the event you lose pressure in the rear or front brakes if you get a leak (the fluid is NOT linked through it)

10"sls brakes will stop an 88" quite adequately regardless of the engine under the bonnet as long as they're set up properly, my 88" started out with 10" single line brakes and i could get the rear wheels hovering under heavy braking with the tdi under the bonnet

i've since upgraded to dual line servo assisted (because i got the bits really cheap and i wanted to experiment) but with 11"sls front brakes (yes eleven inch) the stopping hasn't got that much more powerful (tyre traction is the limitation), it's just that there's less effort required from my leg due to the servo assistance

my daily driver now is a 109 with 200tdi under the bonnet, ok i've got 11" brakes all round but still single line and no servo, i hammer the brakes on hard and i'm almost scraping the galvy off the front bumper

this motor is obviously heavier than my 88" plus i also leave more junk in it so is carrying more weight, the secret to good brakes is to set them up properly and use them regularly (this of course is just MY opinion, others may disagree) both of these motors have been my daily drivers for the last five years so they have been worked hard

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fluid does flow through it as well as putting light on it shuts of front or rear lines that have failed

yes fluid does flow through it but in seperated channels, if you then get a leak in either the front or rear the higher pressure in the other channel then pushes the "shuttle" towards the low pressure channel "flicking" the switch to turn the light on whilst shutting off the leaking line

the front and rear system fluids aren't shared in the PDWA, i really wouldn't bother with it, the reservoir itself has a half height seperator to retain fluid to feed each line (front or rear) so fluid loss is minimised and retaining minimal braking to one or the other axle in the event of a leak

I fitted an electric vacuum pump years ago. I got fed up with trying to sort out knackered butterfly flap set up. It was the best thing I ever did, I used a Hella U28 badged as a Volvo part. 1 1/2 hours and £70 for all new parts. No need for the tank I scrapped mine but have since found selling it may have paid for the pump!

divie said:

I fitted an electric vacuum pump years ago. I got fed up with trying to sort out knackered butterfly flap set up. It was the best thing I ever did, I used a Hella U28 badged as a Volvo part. 1 1/2 hours and £70 for all new parts. No need for the tank I scrapped mine but have since found selling it may have paid for the pump!

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he's sticking a 200tdi in not 2.25d

NiteMare said:

don't bother with the shuttle valve (PDWA - Pressure Differential Warning Actuator) as it's not essential and all it really does is give you a tell tale light in the event you lose pressure in the rear or front brakes if you get a leak (the fluid is NOT linked through it)

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Or worse. Mine had a dodgy seal on the switch and leaked when it lit up making a half bad situation into a fully bad situation quite quickly!

NiteMare said:

10"sls brakes will stop an 88" quite adequately regardless of the engine under the bonnet as long as they're set up properly, my 88" started out with 10" single line brakes and i could get the rear wheels hovering under heavy braking with the tdi under the bonnet

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Also true, unless really loaded up. You _do_ have to learn to drive on the gears and not the brakes on any drum-braked motor though...

Thanks for all the responses, I don't have a tank to sell but pleased to hear that I don't need to buy one!

Re 10"/11"/TLS/SLS etc, I have no issues with the current setup, but have some crazy idea that the missus might drive the truck someday (stop laughing, I'm serious ), hence want to put the best brakes possible on it (without the expense and hassle of fitting discs). Only fitting twin line as that's what the servo'd master cylinder uses and if I need to re plump it I might as well do it properly

Is the vacuum pump a UP28? JAGUAR X TYPE VACUMM PUMP 1 X 43 2C 506 AA UP28 USED | eBay

Cheers.

Re: shuttle valve:

I would put it in. The thing about it is that it will block the fluid flow to the affected section - and that will help the master work properly. I've had a brake failure of that type (lost half with no PDWA) in an Austin-Healey and the loss of resistance/pressure on half the system really screwed up the way the master worked.

Do as you wish but I wouldn;t be without it on my truck.When I went dual boosted brakes on my 109 I added one.

They are very easy to strip clean and rebuild (just O-rings) so even a manky old one can be cleaned up. The same valve was used on 140 and 160 series Volvos so there's another shopping spot if you want to find a used one to clean up.

ajr

Yes but if you use the wrong type of O-rings (that are incompatible with your brake fluid as the PO on mine had) the thing is worse than useless its dangerous! I've still got mine fitted, not saying don't have it just beware they are not a great design!