Just cleaned my drainage tubes.

[dragonheart]

I have been suffering the seashell effect in the passenger side of my Mk3, after a quick Google it was widely suggested that a trombone brush down the drainage hole might be the cure.

Well a £5 eBay trombone brush was duly purchased so the suggested remedy could be carried out.

Trombone brush delivered yesterday, so this morning i have been out and used it.

The process was very simple.

1. Open hood 3/4 way, used something or someone to support it. I used a 5 ltr oil bottle.
2. Poke the trombone brush down through the square hole in the drainage tray behind the seat. Patients is needed here as you may not find the drainage hole first time. Once you have found the drainage hole, feed the brush down through slowly until it exits under the car just in front of the rear wheel. Due to the drainage tubes having a 1 way rubber flap i would say it would not be advisable to pull the brush back up the drainage tube for fear of pulling the 1 way flap in and getting it stuck open.
3. Repeat step 2 as many times as you fell necessary.
4. Put a small funnel in the drainage tube and flush with water (optional).

That's it job done.

As i said with mine i was suffering from the seashell effect, increased road noise.

I completed all of the above steps and now the problem is cured.

If you are suffering from seashell effect, you may as i did have the 1 way rubber flap at the end of the drainage tube stuck open.
To check this you can do as i did, lie down beside the rear wheel, put you hand under the car and locate the drainage tube exit. Insert you little finger and feel for the flap, mine was about an inch inside the tube and clearly open. Go careful when you insert you finger in the tube as the is a sharp point inside which i cut my finger on several times.

When i first inserted the trombone brush and feed it down the drainage tube it became stuck when it encountered the 1 way flap. A little pressure was enough to push the flap through the correct way and allow the trombone brush to pass through.

After this i inserted my little finger into the tube again and this time i could feel the flap closed in the tube. I flushed it through with water and all is now good,

Carry out the above steps and hopefully you to will cure your seashell problem.

[Danstable]

I did the same very recently, read up, bought the trombone cleaner, located the drain tube, popped the cleaner in there, meet some resistance, wiggled it a bit, still stuck.

Pulled the trombone cleaner out....now minus the brush. B*ll*cks!!!

Just contacted the local dealer to find out how far they intend to lower my trousers.

If anyone near Horsham can lend me a hand I'd appreciate it. Just to clarify, I don't want assistance to lower my trousers.

[SmilerFTM]

I just poke an old bit of net curtain wire down it and then some hot soapy water after. Does the trick perfectly.

[Danstable]

I used a domestic drain cleaner first but the amount of sludge that emerged out of the bottom didn't convince me that I'd got it all.

[Riknos]

Danstable said:

I did the same very recently, read up, bought the trombone cleaner, located the drain tube, popped the cleaner in there, meet some resistance, wiggled it a bit, still stuck.

Pulled the trombone cleaner out....now minus the brush. B*ll*cks!!!

Just contacted the local dealer to find out how far they intend to lower my trousers.

If anyone near Horsham can lend me a hand I'd appreciate it. Just to clarify, I don't want assistance to lower my trousers.

I wouldn't bother personally, you'll be stuffed for hundreds. Just keep poking the cleaner down until the brush end falls off. It IS able to fit all the way through, you just need to dislodge whatever is blocking it from coming out the bottom. Maybe try hot water and some soap if not

[sbird]

Do it carefully. I read somewhere that it's a massive PITA to refit the drain tubes.

If it were my car, I would jack the car up and try to push something up from the bottom of the tube.

[Danstable]

Did that also, although not after I had lost the brush. No need to jack the car, once you know where the drain exits it is easy enough to find 'blind'.

[Petrolhead]

Word of advise when using trombone cleaner, do not pull it back out as there are flaps near the bottom to help keep road noise down. Instead push it all the way through and extract if from the bottom of the car

[Dyl]

Bump! I did as above a few months back, trombone cleaner down and pulled through bottom, lots of sludge then noticed the seashell effect. I didn't get another chance to sort until today...

As before, i put the trombone cleaner through, and felt for the flap, all was sorted and feeling fine. Thought "better put it through once more, clear it through". Cue the flap now being completely stuck and my fat fingers can't get in the hole without being ripped apart.

Does anyone have any suggestions as to how best to reset the flap? Tried running trombone cleaner through again but to no avail

[VladD]

Has anyone ever considered sealing the bottom of the drain holes and then filling the tubes with drain cleaner. Leave it there for an hour or two and then flush?

[PATTERNPART]

No!

[VladD]

PATTERNPART said:

No!

Any reason?

[MX-5 Lazza]

Just a poke to clear through then rinse out with water is fine. Using drain cleaner has a number of risks and you certainly wouldn't want any to get on the paintwork or any metal parts, not to mention having to catch it to avoid it reaching the drains/ground water.

[VladD]

MX-5 Lazza said:

Just a poke to clear through then rinse out with water is fine. Using drain cleaner has a number of risks and you certainly wouldn't want any to get on the paintwork or any metal parts, not to mention having to catch it to avoid it reaching the drains/ground water.

By drain cleaner,I mean the stuff you put in sinks and baths to unclog them. You don't have to catch that stuff as it goes down the sewer pipe anyway.

[MX-5 Lazza]

VladD said:

MX-5 Lazza said:

Just a poke to clear through then rinse out with water is fine. Using drain cleaner has a number of risks and you certainly wouldn't want any to get on the paintwork or any metal parts, not to mention having to catch it to avoid it reaching the drains/ground water.

By drain cleaner,I mean the stuff you put in sinks and baths to unclog them. You don't have to catch that stuff as it goes down the sewer pipe anyway.

Bath & toilet water doesn't go to a rain-water drain. It goes into the sewers to be processed at a water treatment plant. Road drains don't go to water treatment plants, they go into the environment. That's why you should never empty your old engine oil, coolant etc. into the drains too.

Regardless, it's over the top for hood drain tubes and too risky to use on any car.

[VladD]

MX-5 Lazza said:

VladD said:

MX-5 Lazza said:

Just a poke to clear through then rinse out with water is fine. Using drain cleaner has a number of risks and you certainly wouldn't want any to get on the paintwork or any metal parts, not to mention having to catch it to avoid it reaching the drains/ground water.

By drain cleaner,I mean the stuff you put in sinks and baths to unclog them. You don't have to catch that stuff as it goes down the sewer pipe anyway.

Bath & toilet water doesn't go to a rain-water drain. It goes into the sewers to be processed at a water treatment plant. Road drains don't go to water treatment plants, they go into the environment. That's why you should never empty your old engine oil, coolant etc. into the drains too.

Regardless, it's over the top for hood drain tubes and too risky to use on any car.

Thanks Lazza. I live out in the sticks, so our house has a septic tanks and the local road I live on doesn't have any drains. I should probably look and see where the rain water collected from our gutters goes.

Anyway, no drain cleaner, but a trombone brush.

Edited by VladD on Monday 18th August 13:57

[WolvesWill]

I tried cleaning mine with a trombone brush but couldn't find the holes (no sniggering at the back). I know where the hole is to get under the plastic trim, but beyond there...not sure where the brush has to go! Any tips?

[dragonheart]

Have you read my instructions at the start of the thread?

[WolvesWill]

Yes still not sure....is the drain hole pretty much straight down, or do you have to angle the brush towards the front/side of the car or what?

[Dyl]

Angle the brush inboard, towards the back of the seat, you should get it with a bit of fiddling.