Radiator cap - slight variations

[Ormin]

Call me a fuss pot, but I started looking at replacement radiator caps on ebay & noticed there is different sizes depth of cap. I was unaware of this. Apparently there are 3/4" & 1" deep filler neck.

It says on the listing for a 3/4" filler neck, that some models use a long reach cap with 1" deep filler neck.

Am I to assume the 1" long reach cap is for the high top radiator, & the 3/4" reach cap is for the lower profile radiator?

I have the high top radiator fitted on my van. I'd like to get the correct cap on there, even though I don't understand what difference it makes. So next question... anyone know why there's two types?

Apologies if I've totally misunderstood the whole issue.

[mowogg]

I know there are 2 types and you cannot mix and match. Not sure when they changed over

[jagnut66]

Hi Ormin,
If you have a high top (Series 2 type) rad then you will need the long reach cap, that is what I was told when I bought my first splitscreen and it is something I've stuck to ever since.
Best wishes,
Mike.

[Ormin]

Thanks Mike! I ordered a long reach type in stainless & I'll see how it compares. Stainless seems a bit of a gimmick, not overly keen on bling, but at the same time stainless is better quality. I got enough rusty panels elsewhere to compensate. Next job in that area will be bending a brass overflow pipe. A nicer way of doing it to the plastic pipe I have atm

Just a note on brass over flow pipes...

I originally had one on a 57 saloon & after that was sold, & I eventually bought a van, I set about making an overflow pipe out of a brass pipe. To get the bends, I filled the pipe with sand & then bent it using a blow torch. Later on I had to remove it, as I needed an electric fan, which was in the way. So, if anyone wants a brass overflow pipe for a high top radiator, let me know & I'll post it to you. I think I know where it is.

[geoberni]

Am I to assume the 1" long reach cap is for the high top radiator, & the 3/4" reach cap is for the lower profile radiator?

Nice theory however.... Just to throw a spanner in the works over this.
I've just replaced the latter flat top style Radiator in my SII with a genuine, period, Hi-Top radiator which I got on ebay.
Guy was selling it as an item cleared out of his late father's garage.
Dad had, like many owners, seemingly built up a bit of a random spares collection and this was a repaired item complete with a little brass plaque giving the repairing workshop's name. It still had the old fabric sticky tape closing the holes off.
Cost me £81 inc P&P, but a bargain compared to £200 a newly built one costs.

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Both Radiators have the same 1" depth to the filler, I've just switched the cap to the 'new' one as it didn't come with a cap.
I suggest you simply get a slim ruler and measure the depth of the fitting, from lip to the step in the bottom of it.
.
If you look at the descriptions of the Caps sold by ESM, they sell 2 depths.

Radiator Cap (4 lbs) for Standard depth (28mm) filler neck - OHV Engines (803/948/1098cc) only.

Short Radiator Cap (4 lbs) for shallow neck radiators (For depth around 21mm). This cap is intended for use with cars fitted with an aftermarket radiator with a 21mm deep filler neck

So only aftermarket Radiators have the shorter item.
Neither of them fit a Side Valve ....

[myoldjalopy]

When I bought a new rad cap for my 'high top' rad, several years ago now, I don't even think there were two types available. I just bought the one that was available and it fitted. If ESM's 'standard depth' cap fits radiators of 803, 948 and 1098cc powered cars, then the same cap must fit both the 'tall' and 'short' rads!

[Ormin]

It's taken a while, but I got a replacement short reach cap to replace the long reach one I bought previously. To conclude... the long reach version seemed too long - ie it touched the lower section inside & had to push the spring down to tighten it. And the short reach is shorter than the cap I had originally. So I've tried three sizes! My original cap seems to fit the best & is between the long & short versions tried. Hope that makes sense.

It's been interesting finding out about these caps & I'll continue to look into it as I go. For now the old rusty one is staying on there.

I enjoyed reading about the original makers plate, a lovely touch with it being an original feature from back in the day. My first & only other vehicle was a 1957 saloon morris minor & it had a transfer from the garage it was originally sold or serviced, just above the speedometer, on the dash.

Thankfully, the other jobs are going well on the van. I was quite surprised the other day, as I'd been really put off the idea of sorting out a car tracker, as there seems so many out there, it's bewildering & quite frankly a boring task to investigate. However, I quickly typed in 'classic car tracker' into YouTube, & the 'carlock' basic came up. I decided to buy one. Fitting it was easy & seems to work ok on the the app, so recommended- every little helps yeah. Did my back in last stages of fitting it though, so been off work nearly all the following week. Sorry for going off topic. Take care out there flexing to do repairs on your vehicles y'all

[Ormin]

Just noticed the 'useful tips' section, so I'll use that in future for eeeerm... useful tips