dobboy 231 2 Cars Posted March 6, 2014 Excuse my ignorance but can someone tell me why the pipes associated with vacuum have a cotton overbraid? TIA Share this post Link to post Share on other sites
nick205 12 5 Cars Posted March 6, 2014 The reason (as I understand it) for brake flexi hoses to be over braided is to reduce hose expansion under pressure. That doesn't tally for vacuum pipes though does it! Possibly to protect from chafing, but then a plastic conduit would be better in that respect. Share this post Link to post Share on other sites
Slo 283 1 Cars Posted March 6, 2014 More like heat protection as its a timing critical component so you really don't want the rubber pipes perishing. Odd thing is most people stuck a bare pipe on that outlasted the advance mechanism Share this post Link to post Share on other sites
calvinhorse 870 Posted March 7, 2014 (edited) Stops them from sucking shut. Also being part of the brake system Needs to be reinforced for safety Well I say needs to be, that's just something I've been told, my car has injection hose for the brake vacuum and has always passed mot Edited March 7, 2014 by calvinhorse 1 Share this post Link to post Share on other sites
dobboy 231 2 Cars Posted March 7, 2014 Can't see the cotton braided pipes I have stopping them from shutting. One thing, at work our guys wrap stuff in cotton tape, basically like a bandage, prior to pouring a hot liquid, >200deg, over it. At times we've broken down this liquid again with heat which had turned solid as it cooled, and the cotton tape is still in very good condition. So I'm guessing its more to do with heat, on safety system pipe work. Strange nobody really knows though! Share this post Link to post Share on other sites
calvinhorse 870 Posted March 7, 2014 Another question you've asked and then decided your own answer.. 1 Share this post Link to post Share on other sites
calvinhorse 870 Posted March 7, 2014 First reply - to stop expansion Second reply - to stop heat Third reply - to stop sucking shut, the over braid is cast into the rubber hose not seperate, it is visible from the outside but isn't just a cover. And you've read all this and still can't find an answer? 1 Share this post Link to post Share on other sites
dobboy 231 2 Cars Posted March 8, 2014 First reply - to stop expansion Second reply - to stop heat Third reply - to stop sucking shut, the over braid is cast into the rubber hose not seperate, it is visible from the outside but isn't just a cover. And you've read all this and still can't find an answer? Is it multiple choice? Share this post Link to post Share on other sites
calvinhorse 870 Posted March 8, 2014 No, all of the answers above answers cover your question 1 Share this post Link to post Share on other sites
dobboy 231 2 Cars Posted March 8, 2014 First reply - to stop expansion Second reply - to stop heat Third reply - to stop sucking shut, the over braid is cast into the rubber hose not seperate, it is visible from the outside but isn't just a cover. And you've read all this and still can't find an answer? No, all of the answers above answers cover your question Calvin, well done, you chose 3 answers and never got any of them correct! The reason that It is provided is to minimise damage caused by friction. Share this post Link to post Share on other sites
Tom Fenton 1,650 Posted March 8, 2014 Well please strike down everyone who has tried to be helpful and answer your question. Hopefully all those people will join me in ignoring everything else you post on this forum. 3 Share this post Link to post Share on other sites
Daviewonder 533 3 Cars Posted March 8, 2014 The reason that It is provided is to minimise damage caused by friction. I don't reckon this it the reason. Why would they only do it to vacuum pipes? I wonder if it's to do with keeping contaminants away which may soften the pipe resulting in collapse. Share this post Link to post Share on other sites
dobboy 231 2 Cars Posted March 8, 2014 Tom, there is a distinct difference between being helpful and guessing. I would rather have no reply than a confidently put wrong reply, and I would guess I'm not the only one. Share this post Link to post Share on other sites
Daviewonder 533 3 Cars Posted March 8, 2014 I'm still not convinced your answer is correct. That puts you in the above category. 1 Share this post Link to post Share on other sites
allanallen 528 2 Cars Posted March 8, 2014 If it's to do with chaffing why aren't the fuel pipes etc over braided? I realise injection pipes have an inner braid before anyone mentions it. It isn't necessarily to do with vacuum either as as far a I'm aware it's only the brake servo vacuum hose that has an overbraid. Fuel pressure reg vac hose etc is just plain hose. Are you looking to replace your pipe or just curious to the reasoning? Share this post Link to post Share on other sites
m@ttc 30 Posted March 8, 2014 the idea is to clamp the cotton in a jubilie/hose clamp, it acts as mechanical strength, if the pipe is pulled the rubber part stays fine because the cotton is taking the srain. Share this post Link to post Share on other sites
dobboy 231 2 Cars Posted March 8, 2014 If it's to do with chaffing why aren't the fuel pipes etc over braided? I realise injection pipes have an inner braid before anyone mentions it. It isn't necessarily to do with vacuum either as as far a I'm aware it's only the brake servo vacuum hose that has an overbraid. Fuel pressure reg vac hose etc is just plain hose. Are you looking to replace your pipe or just curious to the reasoning? Allen, both. I've done my fuel pipes with the R9 stuff, and going to replace vacuum stuff with nicer looking pipe, but curious as to why overbraid is/was used on the vacuum stuff originally. Share this post Link to post Share on other sites
allanallen 528 2 Cars Posted March 8, 2014 No idea why peugeot did it originally, a lot of aftermarket vac hose doesn't have it and obviously silicone vac hose doesn't either. If you're concerned just replace it with like for like, your local motor factors will probably have it. Share this post Link to post Share on other sites
Ryan 99 Posted March 8, 2014 (edited) Most likely it's because that particular hose was a penny per metre cheaper when buying it by the kilometre. Edited March 8, 2014 by Ryan Share this post Link to post Share on other sites
calvinhorse 870 Posted March 8, 2014 (edited) The reason (as I understand it) for brake flexi hoses to be over braided is to reduce hose expansion under pressure. That doesn't tally for vacuum pipes though does it! Possibly to protect from chafing, but then a plastic conduit would be better in that respect. Dobboy - Chafing had been covered Edited March 8, 2014 by calvinhorse 1 Share this post Link to post Share on other sites
calvinhorse 870 Posted March 8, 2014 Seriously is this Surgie? 3 Share this post Link to post Share on other sites
harryskid 193 Posted March 8, 2014 I just can not see why no one can not "Cotton" on to the answer to this! Share this post Link to post Share on other sites
dobboy 231 2 Cars Posted March 8, 2014 Seriously is this Surgie? 1. Yes 2. No 3. Maybe No idea what/who you're on about Calvin. Share this post Link to post Share on other sites
harryskid 193 Posted March 9, 2014 After a bit of researching i think i have the answer. The cotton over is to help the rubber pipe keep its shape! As for using cotton, the original idea was to use nylon but with fashion changes in ladies not wanting to wear the big old cotton knickers and wearing little skimpy ones there was a large stock of cheap cotton going spare! So there you have it! 1 Share this post Link to post Share on other sites
pyrrhic 14 2 Cars Posted March 16, 2014 Ryan seems to have the right answer. I am sure the braided hose was simplest the cheapest Peugeot found to do the job. Share this post Link to post Share on other sites
