--- title: Explained: AdBlue in a Diesel Tank Brynhyfryd canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/brynhyfryd-neath-port-talbot/ location: Brynhyfryd county: Neath Port Talbot latitude: 51.640850 longitude: -3.824880 service: AdBlue in a Diesel Tank updated: 2026-10-17 --- # Why It Happens and How to Prevent It: AdBlue in a Diesel Tank in Brynhyfryd AdBlue already in the diesel tank? In that case set this page aside for now, keep your ignition and motor off, and phone 0333 366 0103. Usually, if the motor has not turned, it is drained and fully cleaned where your vehicle is in Brynhyfryd. The rest of this page explains why it takes place and how to make sure it does not — handy if you're reading before it has happened. ## AdBlue in a diesel car: two tanks, two fillers Many current diesels on the roads around Brynhyfryd and Ynysmaerdy carry two liquids, not one. Diesel goes to your engine. AdBlue goes to your exhaust, where it is sprayed into the gas to clean it, and it lives in a tank of its own. There's a filler on every tank. On a lot of vehicles the two sit side by side under the same flap; on others the AdBlue filler is in your boot or under the bonnet. Diesel gets filled at each forecourt call-out, week in, week out. The AdBlue side is filled far less often, usually from a bottle, and usually by somebody who has to stop and think where it goes. It is in the gap that the error happens. ## How AdBlue in the diesel tank happens in Brynhyfryd It's seldom carelessness. Three things tend to line up. Hurry comes from the warning. Your car tells you as AdBlue runs low, and a dry tank sends it into limp mode — so the top-up gets done in a rush, before work on a driveway off Olive Branch Crescent, or on the way home in the car park outside Crown Inn. Next, your hand goes for the cap it knew on the old vehicle — since a hire car, a new motor or a company car puts the fillers somewhere your last one didn't. A spouted bottle meets no resistance at a diesel filler any more than at an AdBlue one. And so the pour, once begun, carries on. Giants Grave or the middle of Brynhyfryd: it is the same few seconds in both. ## Which filler is for AdBlue, and which for diesel? Before you tip anything, whether on a drive in Warren Hill or a forecourt around Brynhyfryd, check these. They take a few seconds. - Blue and marking: an AdBlue cap is frequently blue, or says "AdBlue", where a diesel cap usually doesn't. Go by the cap, not where it sits. - The size. On plenty of vehicles the AdBlue filler neck is the smaller of the two. - A label inside your fuel flap often shows which fuel goes where, on plenty of cars. Look for it. - In your boot or under the bonnet: that's where your filler sits if it's not by the diesel cap, and the handbook says which. - The person who drove it last. On a hire or company car collected from somewhere like the car park at Briton Ferry, ask before you leave, not when the light comes on. ## AdBlue top-ups that never reach the diesel tank A routine for the day the light comes on, wherever across Neath Port Talbot that is. - Not in a rush on the side of Glanymor Street, not on a slope, not with your motor running: park then switch off first. - Say "AdBlue" out loud as you unscrew the cap, after you find the AdBlue filler and reading it. Silly, perhaps, yet it does the trick. - The two behind a single flap? So make sure the lid on your diesel side stays closed before raising the bottle. - Gently does it, through the bottle's own spout, till it's full or the bottle is empty. - Close the cap, then look once more — making sure your diesel cap stayed shut throughout. Only then, start the vehicle. Find at stage two or three that it has already gone into the diesel side? So stop right there. Leave out stage five altogether. ## Put AdBlue in your diesel tank in Brynhyfryd already? Don't start your engine: that's how the short order of things starts. The fuel pump runs on many diesels as soon as your ignition is switched on — so keep it off. AdBlue doesn't mix with diesel — it sinks to the bottom of that tank, where the fuel is pulled from — so do not top up with diesel to thin it. If you are on a forecourt, whether it is the Esso or the Texaco, ask the attendants to help push the car clear of the pump. If you are on your own driveway in Brynhyfryd, leave the vehicle where it stands. When the motor has been run already, stop safely then switch it off. Brynhyfryd lies under a mile from the M4; on it, take the next junction. About how far did it go? Hopping across Brynhyfryd is smaller work than a trip of under 10 miles to Swansea, so tell us. ## Our arrival in Brynhyfryd, and what occurs next Our van reaches the car wherever it has come to rest — your own driveway, beside Giants Grave and Briton Ferry Boys' Club, or outside the local primary school. Both the work and the price depend on three answers — what fluid, what amount, and if it has run — so our technicians ask. You get that price by phone, before anybody heads out. Then your tank is emptied and the fuel system purged thoroughly. AdBlue crystallises and is corrosive to some of the metals in a fuel system, and so it doesn't wash out on its own — which is why the flush matters more with AdBlue than with petrol. Your filter is flushed, or replaced where it needs to be; fresh diesel goes in; and the vehicle is tested. Before we go, our technicians start the car and make sure that it is running properly. Most jobs are done in about half an hour once our technicians get there, as long as your engine hasn't run — and the pumps we use are safe on a busy forecourt yet quiet at night beside a house. Payment is on the day, not upfront, and you are given the paperwork your insurer wants: an engineer report and a VAT invoice. Misfuelling cover is part of many insurance policies — so make use of the wait to check yours. ## About Brynhyfryd and where it is Brynhyfryd is a suburban area in Neath Port Talbot, situated near the coast and approximately 5 miles from Swansea. Brynhyfryd has a mix of housing types, but is predominantly characterised by terraced homes. Brynhyfryd sits at a relatively low elevation of 34 metres, and its proximity to Swansea makes it a commuter-friendly location. Brynhyfryd is close to nearby places such as Giants Grave and Cwrt Sart. ## Brynhyfryd and Neath Port Talbot: AdBlue drains across the area Brynhyfryd is a residential suburb, and our vans that cover it also work the places around it, Cwrt Sart and Shelone among them, across the SA postcode area. A postcode starting SA11 2 gets our van to you fastest. There's no need to move the vehicle. Anywhere it sits — beside Hengwrt Community Sports Centre, in a layby heading to James Field, at home — that is where it gets cleared. Awkward to explain, like the back of Brynhyfryd House? Close to a county line? Asking beats guessing, so ring. ## For Brynhyfryd motorists, the short version Tip no AdBlue until you have read the cap. Even so AdBlue in the diesel tank? Petrol in Diesel can empty it wherever it stands, wherever in Neath Port Talbot: keep the vehicle off then phone 0333 366 0103.