Thread: My first series 2a project

Well if you haven't seen my Instagram account, then you wouldn't know I now have a registered 2a! To say I am relieved/happy is an understatement. I have been doing a few tweaks here and there since yesterday afternoon, adjusting steering and brakes, tightening Trans top cover plate that was purging oil 🤣

All Good tho, ran like a champ and passed with flying colours. Now to enjoy the beast after just over 3 years since I brought it home.

Well if you aren’t going to post a link to the video, I will. 😁👍



Great work, looks and goes great. 👍

Hahaha - didnt want to bore people. I actually forgot, thast how long its been since doing vids!

While Im posting this, a question for you gurus on brakes. My brakes are SHOCKINGLY BAD! No, not bad as in they are drum brakes, bad as in its like I am using wooden shoes on an drum lines with ice. I have to stop hard on the pedal to get brakes, and its scary on a down hill coming to an intersection cos the only way to slow down is engine braking.

I have new brake shows and cylinders, new brake lines... pedal feels solid (no spunginess). The only items I didnt replace are the drums themselves and the brake master cyl. I am not losing brake fluid. I have recently ordered new drums for the fronts, as I have a very slight pulse on the pedal indicating an out of round drum. However, I suspect this will not fully resolve the problem leading to the last item which is an oversized master cyl.

Any ideas? When I inspected the drums the friction surface was fine, no scoring, blue tinge, hence why I decided to re-use. Oversized master cyl, from what I have gleaned can lead to that wooden pedal feeling without much force applied to the shoes, is this correct? Undersized cyl would require pedal pump as not enough fluid in one hit in the cyl to activate all 4 shoes, is this assumption correct?

If it passed a roadworthy the brakes must have been acceptable ?

Out of interest where did you source the shoes ? I've looked at the **itpart ones and they don't fill me with confidence.

I'm just wondering if you could have the backplates on the wrong wheels but that applies more to a Twin Leading Shoe setup where if fitted wrongly you have brilliant braking in reverse but not the forward direction.

You mention the master cylinder, is it the correct bore for a SWB (assuming you have 10" brakes) ?
The master cylinder bore and the bore and number of pistons in the slave cylinders work together, mixing can cause problems.
Too small a master cylinder then more travel is needed but you get a higher pressure in the system, if the shoes are not properly adjusted you might need a second pump. Too large a master cylinder displaces more fluid but with the same force from you develops less pressure in the system.

Next is to check you are getting a good contact between shoe & drum. Best way I've found is to remove the drum, rub chalk on the linings, refit the drum and turn while someone lightly applies the brakes. This will show if there is good contact. If not you need to file the linings and repeat the process until you get good contact across over 70% of the lining.

My Series III shorty has servo assisted LWB brakes and you can smoke the tyres. My Series I has an original braking system and you need to plan ahead, a couple of times I been praying as the rear of a car that has just pushed in front is getting rather close. Problem is a lot of modern drivers assume everything can decelerate at the same rate their vehicle can......


Colin

Thanks Colin, ill answer in between your Q's below

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If it passed a roadworthy the brakes must have been acceptable ? - They dont test drive, just checked electrics, then put it on a hoist to check under, thats it. Only braking was when moving the Series in and out of the workshop

Out of interest where did you source the shoes ? I've looked at the **itpart ones and they don't fill me with confidence. - Got them from Craddocks, but I recall they where blue packaging

I'm just wondering if you could have the backplates on the wrong wheels but that applies more to a Twin Leading Shoe setup where if fitted wrongly you have brilliant braking in reverse but not the forward direction. - backing plate OK, I remember tripple checking this a number of times, but will check everything when I pull the drums

You mention the master cylinder, is it the correct bore for a SWB (assuming you have 10" brakes) ? - Running the 109 11" single line setup. It was a 1967 2a, no booster. Basically took it off the 109 and put it into the 88, so didnt mix and match - but again ill check

The master cylinder bore and the bore and number of pistons in the slave cylinders work together, mixing can cause problems.
Too small a master cylinder then more travel is needed but you get a higher pressure in the system, if the shoes are not properly adjusted you might need a second pump. Too large a master cylinder displaces more fluid but with the same force from you develops less pressure in the system. - This is why im thinking that maybe the master cyl is the incorrect one, but when I check parts list it seems that the CV /CB types both are interchangeable (88 and 109)

Next is to check you are getting a good contact between shoe & drum. Best way I've found is to remove the drum, rub chalk on the linings, refit the drum and turn while someone lightly applies the brakes. This will show if there is good contact. If not you need to file the linings and repeat the process until you get good contact across over 70% of the lining. - thanks, ill try this when I put on the new drums on

My Series III shorty has servo assisted LWB brakes and you can smoke the tyres. My Series I has an original braking system and you need to plan ahead, a couple of times I been praying as the rear of a car that has just pushed in front is getting rather close. Problem is a lot of modern drivers assume everything can decelerate at the same rate their vehicle can...... - yes, my biggest issue is the sudden unplanned need to brake. I dont expect locking up rubber (which would be preferable) but this is really bad, dangerous in fact. I thought maybe running for a while would bed them in but nothing has changed since my drives. Once I pull the drums ill see where the wear is, maybe as you say the contact patch is small.


Colin[/QUOTE]

Assuming you have the complete brake setup from the lwb, the brakes should be excellent. If you have the front brakes on the right sides, so that forward motion gives you self servo action, you've got it right. If you have braking better going forward than backwards, you have it right. (This braking setup has very poor brakes going backwards!)

Apart from this, about the only likely issues are :-

Wrong master cylinder. You fitted a new one, but did you somehow end up with the wrong one If the wheel cylinders are correct for a 109, and you have a swb m/c you will have too much pedal movement, which is not your issue, but it is just possible it simply the wrong cylinder. It is possible to take the plate off the top of the pedal box, push back the boot, and get a pair of calipers onto the bore of the m/c - 1" or 25.4mm.

As Colin suggests, limited contact of the lining to the drum - This could possibly be because the drum has been machined too far out, or simply because the shoe is badly made. The leading edge of the shoe or very close to it, must touch the drum when the brakes are applied, or you will not get proper servo action.

Another slight possibility is that the shoes have been assembled with a lining that is simply too hard.

My 109 when I got it had the wrong master cylinder fitted and so when I refurbished the system I went and bought the wrong type initially.

I’ve the right one now which has the big master cylinder with the nut shaped cap on the end. Much bigger than the other type.

Re shoes, I replaced all my britpart ones as they are poor quality and replaced them with protex.

Originally Posted by Cadas

My 109 when I got it had the wrong master cylinder fitted and so when I refurbished the system I went and bought the wrong type initially.

I’ve the right one now which has the big master cylinder with the nut shaped cap on the end. Much bigger than the other type.

There are two different bore sizes depending on whether it's for a LWB or SWB.

Colin