• This one, side exit. The outlet faces out to the side and the hose leaves horizontally, then runs across the bay to your catch can. Pick it when there is something sitting directly over the breather, intercooler piping or a brace, and a hose coming straight up would foul it or kink.
• Top exit. The outlet faces straight up and the hose leaves vertically. Shorter, tidier run if your catch can is mounted high on the guard or firewall, but it needs clear air above the rocker cover. See the HPD Top Exit Crankcase Breather.
• Neither one clears a factory top-mount intercooler. Both are for engines with the top-mount gone. Read the fitment section before you choose.
• Everything else is the same. CNC alloy, 4JJ1 and 4JJ3, and both take the HPD -10AN push-in adapter if you are plumbing to a catch can with AN fittings.

• Replaces the factory breather outlet. Direct bolt-on to the rocker cover, no cutting and no welding.
• Gives you a side-facing outlet. Clean horizontal hose run away from hot components and out of tight spots.
• CNC-machined alloy. Built by HPD Special Parts in Thailand. It will not go brittle the way a plastic factory breather does.
• Takes the -10AN adapter. Sold separately, for catch can plumbing in -10AN braided hose.
• Suits OEM and HPD rocker covers. Works with the factory cover or an HPD alloy cover on 4JJ1 and 4JJ3.
• This is a routing part, not a power part. It does not make more power. It gives you a better place to run a breather hose from.

4JJ1-TC 3.0L turbo diesel, 2007 to 2020:

• Holden Rodeo RA7. 2007 to 2008.
• Holden Colorado RC. 2008 to 2012.
• Isuzu D-MAX (4JJ1). 2008 to 2020.
• Isuzu MU-X (4JJ1). 2013 to 2020.

4JJ3-TCX 3.0L turbo diesel, 2020 onwards:

• Isuzu D-MAX (4JJ3). 2020 onwards.
• Isuzu MU-X (4JJ3). 2020 onwards.
• Mazda BT-50 (4JJ3-TCX). 2020 onwards, the Isuzu-platform BT-50.

4JJ3 installs need 4 x 8G (4.2 x 30 mm) pan-head stainless steel self-tapping screws, maximum head diameter 8.5 mm. They are not included. 4JJ1 installs typically reuse the existing hardware.

Not compatible with a factory top-mount intercooler. On a 4JJ1-TC still running the standard top-mount, this breather fouls it. Factory 4JJ1s came with the top-mount sitting over the engine, so unless you have done a front-mount conversion, that is what you have. Check your intercooler before you order, and if you are not sure, send us a photo of your engine bay and we will tell you.

• 1 x HPD side exit crankcase breather for 4JJ1 and 4JJ3, CNC alloy.

Not included:

• Mounting screws for 4JJ3. 4 x 8G (4.2 x 30 mm) pan-head stainless self-tappers, maximum head diameter 8.5 mm.
• The -10AN push-in adapter. Available separately: HPD -10AN push-in breather adapter.
• Catch can hoses and fittings.

• Remove the factory breather outlet and clean the sealing area on the rocker cover.
• Sit the HPD breather in place and mark the holes if your 4JJ3 needs them marked.
• Fasten it with the right hardware and do not overtighten. Snug is enough. These are self-tappers into a rocker cover, not head bolts.
• Use medium-strength thread locker on the screws so vibration does not back them out.
• Route the hose to your catch can and clamp it properly. A leaking breather puts oil mist through the engine bay.
• Tools: a Phillips or hex driver depending on the screws you use, plus the -10AN adapter and braided hose if you are running AN fittings.

• Free express shipping Australia-wide, trackable to all Australian addresses.
• Dispatch: orders placed before 2 PM AEST on a business day go out the same day when the part is in stock.
• Buy now, pay later: Afterpay, Humm, Klarna and Zip. All major credit cards accepted.
• International orders: contact us for a shipping quote.

• Usually in stock and ready to ship.
• Occasionally a 1 to 3 week wait applies depending on demand from HPD in Thailand.
• If you need it by a date, message us before you order and we will confirm stock and the actual dispatch time.

The intercooler is the thing that catches people out. If your 4JJ1-TC still has the factory top-mount intercooler, this breather will not fit, and no amount of hoping will change that. Confirm what you have first.

Returns need the item unused and in its original packaging, so check fitment before you open it. If you are not certain, contact us and we will confirm it before you buy rather than after.

Q: What is the actual difference between the side exit and the top exit?

A: Which way the outlet points. Side exit sends the hose out horizontally, top exit sends it straight up. Choose on your engine bay layout, your intercooler piping and where the catch can sits. Side exit is often the easier one when there is something above the breather and you cannot bring a hose vertically.

Q: Will it fit both 4JJ1 and 4JJ3 without modification?

A: Yes, it bolts on to both. The 4JJ3 needs 4 x 8G (4.2 x 30 mm) pan-head self-tappers, not included. The 4JJ1 usually reuses the existing hardware.

Q: Will it clear my factory top-mount intercooler?

A: No. Not on a 4JJ1-TC with the standard top-mount. It is a clearance conflict, not a tight squeeze.

Q: How do I know whether I have a top-mount or a front-mount?

A: A factory 4JJ1 has the top-mount sitting on top of the engine. Fitting a front-mount is a big job, so if it had been done you would know about it. If nobody has changed it, it is the factory top-mount.

Q: Do I need the -10AN adapter?

A: Only if your catch can runs -10AN fittings. It gives you a proper sealed connection. Otherwise use appropriately sized hose and clamps to suit your catch can.

Q: Where do I get the screws for the 4JJ3?

A: Any hardware or fastener shop stocks 8 gauge (4.2 x 30 mm) stainless pan-head self-tapping screws. Make sure the head is no more than 8.5 mm across. Ask us when you order and we may be able to put them in the box.

Q: Can I vent it to atmosphere instead of running a catch can?

A: Technically it will work, but we would not do it. Venting crankcase gas straight out puts oil mist and vapour into the engine bay. A catch can traps the oil and lets the clean air out, which is what you actually want.

Q: Will it work with my HPD alloy rocker cover?

A: Yes. It suits the OEM cover and the HPD alloy cover on 4JJ1 and 4JJ3.

Q: Can I return it if it does not fit?

A: Yes, provided it is unused and in the original packaging. Check your intercooler setup first and it will not come to that.