| Author | Message | ||
     Dave_02_1200 |
How/why does this work? ie Does the Brake Cleaner displace oxygen and cause an over-rich mixture that slows the idle speed or is something else going on? I have heard of using propane too. Does that work similarly? I know it works but I just want to understand the operating principles behind the test. | ||
| Coxster |
I used WD-40 on my 54 Ford. The engine changes speed when you seal up a leak, usually slows down because the air leak made the car run lean. Haven't tried it on the M2 yet, but it's on the to-do list for January | ||
| Greg_cifu |
Yup. Flammable fluids work because they burn and change the engine speed. Ditto for propane. WD-40 can work because it's got oil in it that will partly block the leak or change the amount it's leaking. It's not chemically important what is changing. The fact that anything changes at all is the hint that the seal is leaking (if it were sealed tight, nothing would happen when you sprayed it). If you spray at the joint and anything changes (speeds up OR slows down), the seals need to be replaced. | ||
| Ltbuell |
...brake cleaner will remove/discolor anything painted(cylinder heads,etc) and is flammable so you really want to use a non flammable aerosol...even the fumes will have an effect on engine speed as they are injested through the carb/f.i.air intake and can give a false engine speed.WD-40 has a much lower flash point(yes,it will ignite)but is much safer and just using small "spurts" won't create any "issues" other than find out if you have an intake leak....remember too that your exhaust headers are right near there and getting any of those liquid/aerosols on them can have a "result" not wanting to happen....just use common sense and safety....don't want to hear about unfortunate mishaps...only final solutions and positive results.LT | ||
| Dave_02_1200 |
Would squirting motor oil on the seals with a pump oil can be a safer alternative? | ||
| Kalali |
I think whatever material used for this method of diagnostics need to be in an aerosol format so it can be "sucked" into the intake tract if the seal has been compromised. I believe what was said in the first post, e.g., the aerosol displaces the oxygen, is the working principle of this method. | ||
| Natexlh1000 |
I would suggest WD40 not brakleen. I would be nervous allowing brake cleaner near any seals or rubber. If WD40 gets in, smoke comes out the exhaust too as well as the RPM changing. | ||
| Buelljunkie |
I agree with Nate...brake parts cleaner can be extremely damaging to unintended parts (i.e.-frame and head paint), and I've never had WD40 damage anything. | ||
| Reepicheep |
I think it is just a language issue. http://www.amazon.com/Break-Free-Cleaner-Lubricant -Preservative-Aerosol/dp/B0050GW73C/ref=pd_sbs_sg_ 2 I bet the stuff packaged in the EU is more like what we would call WD-40 here in the US. |
