Plus 2 front calipers mismatched

[The Veg]

You may have seen in another thread that I was finally able to take a short drive in my Plus 2, which I had to cut short due to a leak from the right front caliper. I've now got both front calipers off and I've found that the calipers are different types! The right front -the one that leaked- is the later type with the wire clip on the outer seal, and the left front is the earlier type with no wire clip. I'm aware that my car is from the transitional period between early and late features but that's ridiculous! (yeah I know...probably the work of a DPO!)

The early type caliper seems to have some rust-issues that are keeping the pistons from moving freely; I gave it a good fight but only got one out. I'm thinking that this one should be replaced with a later type to match the other one; that said, am I correct to assume that the later type is in any way better than the early type?

[mbell]

One difference is I am aware of is that at some point the calipers transitioned to metric threads for the hydraulic connections. Later cars have metric calipers rather than imperial. So you need to be careful to make sure you use the right fittings and ideally have matching threads to avoid issue in the future.

[denicholls2]

And might the original leak be attributable to a mismatch between caliper and hose on this basis? Brake fluid regularly going missing is one reason to sell a car on, I suppose...

[The Veg]

And might the original leak be attributable to a mismatch between caliper and hose on this basis? Brake fluid regularly going missing is one reason to sell a car on, I suppose...

No, it leaked around a piston.

[nmauduit]

One difference is I am aware of is that at some point the calipers transitioned to metric threads for the hydraulic connections. Later cars have metric calipers rather than imperial. So you need to be careful to make sure you use the right fittings and ideally have matching threads to avoid issue in the future.

I understand that plus2 use version 16 of the Girling calipers, which usually can be identified by the cast number

16 then 16P till about 1969, 16PB 69 till 73 approx., then metric (16M ? or M16, which also came in a variety of versions including vented ones)

unless in a rush to get the car back on the road, I would source a pair of matching or at least identical calipers, they come by used for not much money, and rebuild them to know where I stand, and knowing I (or the next keeper) will be able to renew with a kit without having to remember what is on which side ...

[The Veg]

I've now got both front calipers off and I've found that the calipers are different types! The right front -the one that leaked- is the later type with the wire clip on the outer seal, and the left front is the earlier type with no wire clip. I'm aware that my car is from the transitional period between early and late features but that's ridiculous! (yeah I know...probably the work of a DPO!)

Just as a humourous aside, I called one of the Usual Suspects about this and he said he wouldn't be surprised of the factory actually put the mis-matched calipers on the car, given Lotus' reputation for using whatever they could in a pinch.

[Andy8421]

Just as a humourous aside, I called one of the Usual Suspects about this and he said he wouldn't be surprised of the factory actually put the mis-matched calipers on the car, given Lotus' reputation for using whatever they could in a pinch.

I have heard stories (probably apocryphal) about cars leaving the factory with a drum on one side at the front and a disc on the other - only discovered during the first service when the owner mentions 'it pulls a bit to the left'.

I guess it could be possible when different spec variants of the same car were going down the same line (the 'cooking' model had drum brakes, but the GT had discs..) and the assembly workers got out of sync with each other.

I am also quite prepared to believe that Lotus would have fitted whatever they could get away with when the car was originally built to get it out the door.

[elated]

Certainly apocryphal in relation to all post 1963 Lotus production but why let the facts get in the way of a good story.
Gordon

[The Veg]

Another update...been poking around to find a caliper to get a matching setup, the one US-based Usual Suspect who has calipers in stock only has early lefts and late rights, exactly what I already have! Looked on a couple of UK Suspects sites and they have what I need but require exchange, which nixes it because the cost to ship a core over there will probably be quite prohibitive, remembering the eye-watering quotes I got for sending a mere five-ounce packet of wire that somebody in this forum wanted to buy from me a while back.

I'll search around a bit more, but I do want to get it roadworthy again sooner than later as the oppressive summer heat is starting to fade. Worst case is stick with what I've got and be doomed to having to buy two different rebuild kits instead of one. I wonder if putting the un-used bits from those kits in a vacuum-seal bag will preserve them until the next rebuild is needed? We have one of those food-sealer things in the kitchen...

[JJ66]

Hi There, Apologies if you have already tried this route, but you may have more luck finding a matching caliper by contacting people who restore or break Triumph Spitfires and GT6's. The calipers were common to the GT6 and changed over at the same time around 1971.

Regards, Jonathan

[The Veg]

Hi There, Apologies if you have already tried this route, but you may have more luck finding a matching caliper by contacting people who restore or break Triumph Spitfires and GT6's. The calipers were common to the GT6 and changed over at the same time around 1971.

No worries Jonathan! I'm already down that path- just placed an order and it should be here in a week or so.

[Spyder fan]

Edited due to brain fade, see next 2 posts

[alanr]

Differences I understand are:-
Hose thread is either metric or imperial. Bleed nipple metric or imperial. Pad retainer pins either 4.5mm or 6mm. Pad shims different.

Alan.

[Spyder fan]

Differences I understand are:-
Hose thread is either metric or imperial. Bleed nipple metric or imperial. Pad retainer pins either 4.5mm or 6mm. Pad shims different.

Alan.

Just checked on SJ Sportscars and you are correct. I no doubt ordered the new brake pipes at the same time. It was over 14 years ago!

https://www.sjsportscars.com/parts-and- ... rchresults

£66 per side, new and no exchange. Add pads and pipes and it’s job done.